Major code refacroting

83 files changed, 457 insertions, 833 deletions

diff --git a/src/org/traccar/protocol/ApelProtocolDecoder.java b/src/org/traccar/protocol/ApelProtocolDecoder.java
index c772ce6f7..619831f0f 100644
--- a/src/org/traccar/protocol/ApelProtocolDecoder.java
+++ b/src/org/traccar/protocol/ApelProtocolDecoder.java
@@ -29,6 +29,7 @@ import org.jboss.netty.channel.Channel;
 import org.jboss.netty.channel.ChannelHandlerContext;
 
 import org.traccar.BaseProtocolDecoder;
+import org.traccar.Context;
 import org.traccar.database.DataManager;
 import org.traccar.helper.Crc;
 import org.traccar.helper.Log;
@@ -37,12 +38,11 @@ import org.traccar.model.Position;
 
 public class ApelProtocolDecoder extends BaseProtocolDecoder {
 
-    private long deviceId;
     private long lastIndex;
     private long newIndex;
 
-    public ApelProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public ApelProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     /*
@@ -140,13 +140,7 @@ public class ApelProtocolDecoder extends BaseProtocolDecoder {
             int length = buf.readUnsignedShort();
             buf.skipBytes(length);
             length = buf.readUnsignedShort();
-            String imei = buf.readBytes(length).toString(Charset.defaultCharset());
-            try {
-                deviceId = getDataManager().getDeviceByImei(imei).getId();
-                loadLastIndex();
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + imei + " (id - " + id + ")");
-            }
+            identify(buf.readBytes(length).toString(Charset.defaultCharset()));
         }
         
         else if (type == MSG_TYPE_LAST_LOG_INDEX) {
@@ -158,7 +152,7 @@ public class ApelProtocolDecoder extends BaseProtocolDecoder {
         }
 
         // Position
-        else if (deviceId != 0 && (type == MSG_TYPE_CURRENT_GPS_DATA || type == MSG_TYPE_STATE_FULL_INFO_T104 || type == MSG_TYPE_LOG_RECORDS)) {
+        else if (hasDeviceId() && (type == MSG_TYPE_CURRENT_GPS_DATA || type == MSG_TYPE_STATE_FULL_INFO_T104 || type == MSG_TYPE_LOG_RECORDS)) {
             List<Position> positions = new LinkedList<Position>();
 
             int recordCount = 1;
@@ -169,7 +163,7 @@ public class ApelProtocolDecoder extends BaseProtocolDecoder {
             for (int j = 0; j < recordCount; j++) {
                 Position position = new Position();
                 ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
-                position.setDeviceId(deviceId);
+                position.setDeviceId(getDeviceId());
 
                 // Message index
                 int subtype = type;
diff --git a/src/org/traccar/protocol/AplicomProtocolDecoder.java b/src/org/traccar/protocol/AplicomProtocolDecoder.java
index c47731759..aee1517e4 100644
--- a/src/org/traccar/protocol/AplicomProtocolDecoder.java
+++ b/src/org/traccar/protocol/AplicomProtocolDecoder.java
@@ -23,6 +23,7 @@ import org.jboss.netty.channel.Channel;
 import org.jboss.netty.channel.ChannelHandlerContext;
 
 import org.traccar.BaseProtocolDecoder;
+import org.traccar.Context;
 import org.traccar.database.DataManager;
 import org.traccar.helper.Log;
 import org.traccar.model.ExtendedInfoFormatter;
@@ -30,8 +31,8 @@ import org.traccar.model.Position;
 
 public class AplicomProtocolDecoder extends BaseProtocolDecoder {
 
-    public AplicomProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public AplicomProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final long IMEI_BASE_TC65_V20 = 0x1437207000000L;
@@ -128,13 +129,12 @@ public class AplicomProtocolDecoder extends BaseProtocolDecoder {
         // Create new position
         Position position = new Position();
         ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(imei)) {
             return null;
         }
 
+        position.setDeviceId(getDeviceId());
+
         // Event
         extendedInfo.set("event", buf.readUnsignedByte());
         buf.readUnsignedByte();
diff --git a/src/org/traccar/protocol/Ardi01ProtocolDecoder.java b/src/org/traccar/protocol/Ardi01ProtocolDecoder.java
index e25ff1c57..4e90134ae 100644
--- a/src/org/traccar/protocol/Ardi01ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Ardi01ProtocolDecoder.java
@@ -31,8 +31,8 @@ import java.util.regex.Pattern;
 
 public class Ardi01ProtocolDecoder extends BaseProtocolDecoder {
 
-    public Ardi01ProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public Ardi01ProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -68,14 +68,11 @@ public class Ardi01ProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Detect device
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
-        
+        position.setDeviceId(getDeviceId());
+
         // Date and time
         Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
         time.clear();
diff --git a/src/org/traccar/protocol/AtrackProtocolDecoder.java b/src/org/traccar/protocol/AtrackProtocolDecoder.java
index 607b3e558..e2f3e924f 100644
--- a/src/org/traccar/protocol/AtrackProtocolDecoder.java
+++ b/src/org/traccar/protocol/AtrackProtocolDecoder.java
@@ -35,8 +35,8 @@ import org.traccar.model.Position;
 
 public class AtrackProtocolDecoder extends BaseProtocolDecoder {
 
-    public AtrackProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public AtrackProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final int MSG_HEARTBEAT = 0x1A;
@@ -91,18 +91,13 @@ public class AtrackProtocolDecoder extends BaseProtocolDecoder {
         int index = buf.readUnsignedShort();
 
         // Get device id
-        long deviceId;
-        long rawId = buf.readLong();
-        String id = String.valueOf(rawId);
-        try {
-            deviceId = getDataManager().getDeviceByImei(id).getId();
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + id);
+        long id = buf.readLong();
+        if (!identify(String.valueOf(id))) {
             return null;
         }
-        
+
         // Send acknowledgement
-        sendResponse(channel, remoteAddress, rawId, index);
+        sendResponse(channel, remoteAddress, id, index);
 
         List<Position> positions = new LinkedList<Position>();
 
@@ -110,7 +105,7 @@ public class AtrackProtocolDecoder extends BaseProtocolDecoder {
 
             // Create new position
             Position position = new Position();
-            position.setDeviceId(deviceId);
+            position.setDeviceId(getDeviceId());
             ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
 
             // Date and time
diff --git a/src/org/traccar/protocol/AutoFon45ProtocolDecoder.java b/src/org/traccar/protocol/AutoFon45ProtocolDecoder.java
index df98fa93b..c72139c50 100644
--- a/src/org/traccar/protocol/AutoFon45ProtocolDecoder.java
+++ b/src/org/traccar/protocol/AutoFon45ProtocolDecoder.java
@@ -32,15 +32,14 @@ import org.traccar.model.Position;
 import java.util.*;
 
 public class AutoFon45ProtocolDecoder extends BaseProtocolDecoder {
-    private long deviceId;
 
     private static double convertCoordinate(short degrees, int raw) {
         double seconds = (raw >> 4 & 0xffffff) / 600000.0;
         return (degrees + seconds) * ((raw & 0x0f) == 0 ? -1 : 1);
     }
 
-    public AutoFon45ProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public AutoFon45ProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     @Override
@@ -54,10 +53,7 @@ public class AutoFon45ProtocolDecoder extends BaseProtocolDecoder {
             buf.readBytes(bytes);
 
             String imei = ChannelBufferTools.readHexString(ChannelBuffers.wrappedBuffer(bytes, 1, 16), 16).substring(1);
-            try {
-                deviceId = getDataManager().getDeviceByImei(imei).getId();
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + imei);
+            if (!identify(imei)) {
                 return null;
             }
 
@@ -74,7 +70,7 @@ public class AutoFon45ProtocolDecoder extends BaseProtocolDecoder {
             // Create new position
             Position position = new Position();
             ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
-            position.setDeviceId(deviceId);
+            position.setDeviceId(getDeviceId());
 
             short status = buf.readUnsignedByte();
             extendedInfo.set("alarm", (status & 0x80) != 0);
diff --git a/src/org/traccar/protocol/AutoFonProtocolDecoder.java b/src/org/traccar/protocol/AutoFonProtocolDecoder.java
index fbc142846..2c563d6d2 100644
--- a/src/org/traccar/protocol/AutoFonProtocolDecoder.java
+++ b/src/org/traccar/protocol/AutoFonProtocolDecoder.java
@@ -30,16 +30,14 @@ import java.util.*;
 
 public class AutoFonProtocolDecoder extends BaseProtocolDecoder {
 
-    public AutoFonProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public AutoFonProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final int MSG_LOGIN = 0x10;
     private static final int MSG_LOCATION = 0x11;
     private static final int MSG_HISTORY = 0x12;
 
-    private long deviceId;
-
     private static double convertCoordinate(int raw) {
         double result = raw / 1000000;
         result += (raw % 1000000) / 600000.0;
@@ -51,7 +49,7 @@ public class AutoFonProtocolDecoder extends BaseProtocolDecoder {
         // Create new position
         Position position = new Position();
         ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
-        position.setDeviceId(deviceId);
+        position.setDeviceId(getDeviceId());
 
         if (!history) {
             buf.readUnsignedByte(); // interval
@@ -127,10 +125,7 @@ public class AutoFonProtocolDecoder extends BaseProtocolDecoder {
             buf.readUnsignedByte(); // software version
 
             String imei = ChannelBufferTools.readHexString(buf, 16).substring(1);
-            try {
-                deviceId = getDataManager().getDeviceByImei(imei).getId();
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + imei);
+            if (!identify(imei)) {
                 return null;
             }
 
diff --git a/src/org/traccar/protocol/BceProtocolDecoder.java b/src/org/traccar/protocol/BceProtocolDecoder.java
index a1c45758c..2f96ab317 100644
--- a/src/org/traccar/protocol/BceProtocolDecoder.java
+++ b/src/org/traccar/protocol/BceProtocolDecoder.java
@@ -33,8 +33,8 @@ import org.traccar.model.Position;
 
 public class BceProtocolDecoder extends BaseProtocolDecoder {
 
-    public BceProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public BceProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final int DATA_TYPE = 7;
@@ -57,11 +57,7 @@ public class BceProtocolDecoder extends BaseProtocolDecoder {
         ChannelBuffer buf = (ChannelBuffer) msg;
         
         String imei = String.format("%015d", buf.readLong());
-        long deviceId;
-        try {
-            deviceId = getDataManager().getDeviceByImei(imei).getId();
-        } catch (Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(imei)) {
             return null;
         }
 
@@ -77,7 +73,7 @@ public class BceProtocolDecoder extends BaseProtocolDecoder {
 
                 Position position = new Position();
                 ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
-                position.setDeviceId(deviceId);
+                position.setDeviceId(getDeviceId());
 
                 int structEnd = buf.readUnsignedByte() + buf.readerIndex();
 
diff --git a/src/org/traccar/protocol/BoxProtocolDecoder.java b/src/org/traccar/protocol/BoxProtocolDecoder.java
index cdbd3932e..d2de48489 100644
--- a/src/org/traccar/protocol/BoxProtocolDecoder.java
+++ b/src/org/traccar/protocol/BoxProtocolDecoder.java
@@ -31,11 +31,9 @@ import org.traccar.model.ExtendedInfoFormatter;
 import org.traccar.model.Position;
 
 public class BoxProtocolDecoder extends BaseProtocolDecoder {
-    
-    private Long deviceId;
 
-    public BoxProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public BoxProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -63,12 +61,7 @@ public class BoxProtocolDecoder extends BaseProtocolDecoder {
             
             int index = sentence.indexOf(',', 2) + 1;
             String id = sentence.substring(index, sentence.indexOf(',', index));
-
-            try {
-                deviceId = getDataManager().getDeviceByImei(id).getId();
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + id);
-            }
+            identify(id);
         }
         
         else if (sentence.startsWith("L,")) {
@@ -81,7 +74,7 @@ public class BoxProtocolDecoder extends BaseProtocolDecoder {
 
             // Create new position
             Position position = new Position();
-            position.setDeviceId(deviceId);
+            position.setDeviceId(getDeviceId());
             ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
 
             Integer index = 1;
diff --git a/src/org/traccar/protocol/CalAmpProtocolDecoder.java b/src/org/traccar/protocol/CalAmpProtocolDecoder.java
index 8fe75bf93..04ac8f165 100644
--- a/src/org/traccar/protocol/CalAmpProtocolDecoder.java
+++ b/src/org/traccar/protocol/CalAmpProtocolDecoder.java
@@ -33,8 +33,8 @@ import org.traccar.model.Position;
 
 public class CalAmpProtocolDecoder extends BaseProtocolDecoder {
 
-    public CalAmpProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public CalAmpProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final int MSG_NULL = 0;
@@ -91,8 +91,6 @@ public class CalAmpProtocolDecoder extends BaseProtocolDecoder {
 
         ChannelBuffer buf = (ChannelBuffer) msg;
 
-        Long deviceId = null;
-
         // Check options header
         if ((buf.getByte(buf.readerIndex()) & 0x80) != 0) {
 
@@ -112,14 +110,7 @@ public class CalAmpProtocolDecoder extends BaseProtocolDecoder {
                     }
                 }
 
-                // Find device in database
-                String stringId = String.valueOf(id);
-                try {
-                    deviceId = getDataManager().getDeviceByImei(stringId).getId();
-                } catch(Exception error) {
-                    Log.warning("Unknown device - " + stringId);
-                }
-
+                identify(String.valueOf(id));
             }
 
             // Identifier type
@@ -150,8 +141,7 @@ public class CalAmpProtocolDecoder extends BaseProtocolDecoder {
         }
 
         // Unidentified device
-        if (deviceId == null) {
-            Log.warning("Unknown device");
+        if (!hasDeviceId()) {
             return null;
         }
 
@@ -170,8 +160,8 @@ public class CalAmpProtocolDecoder extends BaseProtocolDecoder {
 
             // Create new position
             Position position = new Position();
-            position.setDeviceId(deviceId);
-            ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter("calamp");
+            position.setDeviceId(getDeviceId());
+            ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
 
             // Location data
             position.setTime(new Date(buf.readUnsignedInt() * 1000));
diff --git a/src/org/traccar/protocol/CarTrackProtocolDecoder.java b/src/org/traccar/protocol/CarTrackProtocolDecoder.java
index 170db3130..425115fe9 100644
--- a/src/org/traccar/protocol/CarTrackProtocolDecoder.java
+++ b/src/org/traccar/protocol/CarTrackProtocolDecoder.java
@@ -33,8 +33,8 @@ import org.traccar.model.Position;
 
 public class CarTrackProtocolDecoder extends BaseProtocolDecoder {
 
-    public CarTrackProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public CarTrackProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -77,13 +77,10 @@ public class CarTrackProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Get device by unique identifier
-        String id = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(id).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + id);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Command
         extendedInfo.set("command", parser.group(index++));
diff --git a/src/org/traccar/protocol/CarscopProtocolDecoder.java b/src/org/traccar/protocol/CarscopProtocolDecoder.java
index e56036d0b..e7c4d6192 100644
--- a/src/org/traccar/protocol/CarscopProtocolDecoder.java
+++ b/src/org/traccar/protocol/CarscopProtocolDecoder.java
@@ -32,13 +32,10 @@ import org.traccar.model.Position;
 
 public class CarscopProtocolDecoder extends BaseProtocolDecoder {
 
-    private Long deviceId;
-
-    public CarscopProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public CarscopProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
-    // Very similar to TK103 protocol
     static private Pattern pattern = Pattern.compile(
             "\\*.*" +
             "(\\d{2})(\\d{2})(\\d{2})" + // Time (HHMMSS)
@@ -64,13 +61,9 @@ public class CarscopProtocolDecoder extends BaseProtocolDecoder {
         int index = sentence.indexOf("UB05");
         if (index != -1) {
             String imei = sentence.substring(index + 4, index + 4 + 15);
-            try {
-                deviceId = getDataManager().getDeviceByImei(imei).getId();
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + imei);
-            }
+            identify(imei);
         }
-        if (deviceId == null) {
+        if (!hasDeviceId()) {
             return null;
         }
 
@@ -82,7 +75,7 @@ public class CarscopProtocolDecoder extends BaseProtocolDecoder {
 
         // Create new position
         Position position = new Position();
-        position.setDeviceId(deviceId);
+        position.setDeviceId(getDeviceId());
         ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
         index = 1;
 
diff --git a/src/org/traccar/protocol/CellocatorProtocolDecoder.java b/src/org/traccar/protocol/CellocatorProtocolDecoder.java
index 178e17530..a61c5b79f 100644
--- a/src/org/traccar/protocol/CellocatorProtocolDecoder.java
+++ b/src/org/traccar/protocol/CellocatorProtocolDecoder.java
@@ -33,8 +33,8 @@ import org.traccar.model.Position;
 
 public class CellocatorProtocolDecoder extends BaseProtocolDecoder {
 
-    public CellocatorProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public CellocatorProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private String readImei(ChannelBuffer buf) {
@@ -93,7 +93,7 @@ public class CellocatorProtocolDecoder extends BaseProtocolDecoder {
 
         buf.skipBytes(4); // system code
         int type = buf.readUnsignedByte();
-        long deviceId = buf.readUnsignedInt();
+        long deviceUniqueId = buf.readUnsignedInt();
         
         if (type != MSG_CLIENT_SERIAL) {
             buf.readUnsignedShort(); // communication control
@@ -101,7 +101,7 @@ public class CellocatorProtocolDecoder extends BaseProtocolDecoder {
         byte packetNumber = buf.readByte();
 
         // Send reply
-        sendReply(channel, deviceId, packetNumber);
+        sendReply(channel, deviceUniqueId, packetNumber);
 
         // Parse location
         if (type == MSG_CLIENT_STATUS) {
@@ -109,13 +109,11 @@ public class CellocatorProtocolDecoder extends BaseProtocolDecoder {
             ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
             
             // Device identifier
-            try {
-                position.setDeviceId(getDataManager().getDeviceByImei(String.valueOf(deviceId)).getId());
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + deviceId);
+            if (!identify(String.valueOf(deviceUniqueId))) {
                 return null;
             }
-            
+            position.setDeviceId(getDeviceId());
+
             buf.readUnsignedByte(); // hardware version
             buf.readUnsignedByte(); // software version
             buf.readUnsignedByte(); // protocol version
diff --git a/src/org/traccar/protocol/EasyTrackProtocolDecoder.java b/src/org/traccar/protocol/EasyTrackProtocolDecoder.java
index bbf1ce817..c32ac2228 100644
--- a/src/org/traccar/protocol/EasyTrackProtocolDecoder.java
+++ b/src/org/traccar/protocol/EasyTrackProtocolDecoder.java
@@ -32,11 +32,10 @@ import org.traccar.model.Position;
 
 public class EasyTrackProtocolDecoder extends BaseProtocolDecoder {
 
-    public EasyTrackProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public EasyTrackProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
-    //ET,358155100003016,HB,A,0d081e,07381e,8038ee09,03d2e9be,004f,0000,40c00000,0f,100,0000,00037c,29
     static private Pattern pattern = Pattern.compile(
             "\\*..," +                          // Manufacturer
             "(\\d+)," +                         // IMEI
@@ -82,19 +81,16 @@ public class EasyTrackProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Get device by IMEI
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Command
         extendedInfo.set("command", parser.group(index++));
 
         // Validity
-        position.setValid(parser.group(index++).compareTo("A") == 0 ? true : false);
+        position.setValid(parser.group(index++).compareTo("A") == 0);
         
         // Date
         Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
diff --git a/src/org/traccar/protocol/EelinkProtocolDecoder.java b/src/org/traccar/protocol/EelinkProtocolDecoder.java
index e63189dae..929153033 100644
--- a/src/org/traccar/protocol/EelinkProtocolDecoder.java
+++ b/src/org/traccar/protocol/EelinkProtocolDecoder.java
@@ -35,8 +35,8 @@ import org.traccar.model.Position;
 
 public class EelinkProtocolDecoder extends BaseProtocolDecoder {
 
-    public EelinkProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public EelinkProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private String readImei(ChannelBuffer buf) {
@@ -60,9 +60,7 @@ public class EelinkProtocolDecoder extends BaseProtocolDecoder {
     private static final int MSG_OBD = 0x07;
     private static final int MSG_INTERACTIVE = 0x80;
     private static final int MSG_DATA = 0x81;
-    
-    private Long deviceId;
-    
+
     private void sendResponse(Channel channel, int type, int index) {
         if (channel != null) {
             ChannelBuffer response = ChannelBuffers.buffer(7);
@@ -91,15 +89,10 @@ public class EelinkProtocolDecoder extends BaseProtocolDecoder {
         }
         
         if (type == MSG_LOGIN) {
-            String imei = ChannelBufferTools.readHexString(buf, 16).substring(1);
-            try {
-                deviceId = getDataManager().getDeviceByImei(imei).getId();
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + imei);
-            }
+            identify(ChannelBufferTools.readHexString(buf, 16).substring(1));
         }
         
-        else if (deviceId != null &&
+        else if (hasDeviceId() &&
                 (type == MSG_GPS ||
                  type == MSG_ALARM ||
                  type == MSG_STATE ||
@@ -107,7 +100,7 @@ public class EelinkProtocolDecoder extends BaseProtocolDecoder {
             
             // Create new position
             Position position = new Position();
-            position.setDeviceId(deviceId);
+            position.setDeviceId(getDeviceId());
             
             ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
             extendedInfo.set("index", index);
diff --git a/src/org/traccar/protocol/EnforaProtocolDecoder.java b/src/org/traccar/protocol/EnforaProtocolDecoder.java
index 8f5391fd6..430693189 100644
--- a/src/org/traccar/protocol/EnforaProtocolDecoder.java
+++ b/src/org/traccar/protocol/EnforaProtocolDecoder.java
@@ -35,8 +35,8 @@ import org.traccar.model.Position;
 
 public class EnforaProtocolDecoder extends BaseProtocolDecoder {
 
-    public EnforaProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public EnforaProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -101,12 +101,10 @@ public class EnforaProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Get device by IMEI
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(imei)) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Time
         Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
diff --git a/src/org/traccar/protocol/Ev603ProtocolDecoder.java b/src/org/traccar/protocol/Ev603ProtocolDecoder.java
index 7c596d479..acf359daf 100644
--- a/src/org/traccar/protocol/Ev603ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Ev603ProtocolDecoder.java
@@ -33,10 +33,8 @@ import org.traccar.model.Position;
 

 public class Ev603ProtocolDecoder extends BaseProtocolDecoder{

 

-    private Long deviceId;

-

-    public Ev603ProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {

-        super(dataManager, protocol, properties);

+    public Ev603ProtocolDecoder(String protocol) {

+        super(protocol);

     }

 

     private static final Pattern pattern = Pattern.compile(

@@ -58,25 +56,19 @@ public class Ev603ProtocolDecoder extends BaseProtocolDecoder{
 

         // Detect device ID

         if (sentence.startsWith("!1,")) {

-            String imei = sentence.substring(3);

-            try {

-                deviceId = getDataManager().getDeviceByImei(imei).getId();

-            } catch(Exception error) {

-                Log.warning("Unknown device - " + imei);

-                return null;

-            }

+            identify(sentence.substring(3));

         }

 

         else if (sentence.startsWith("!A,")) {

             // Parse message

             Matcher parser = pattern.matcher(sentence);

-            if (deviceId == null || !parser.matches()) {

+            if (!hasDeviceId() || !parser.matches()) {

                 return null;

             }

 

             // Create new position

             Position position = new Position();

-            position.setDeviceId(deviceId);

+            position.setDeviceId(getDeviceId());

             ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());

             Integer index = 1;

 

diff --git a/src/org/traccar/protocol/FreedomProtocolDecoder.java b/src/org/traccar/protocol/FreedomProtocolDecoder.java
index 21e6f9abc..f8ab610b1 100644
--- a/src/org/traccar/protocol/FreedomProtocolDecoder.java
+++ b/src/org/traccar/protocol/FreedomProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class FreedomProtocolDecoder extends BaseProtocolDecoder {
 
-    public FreedomProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public FreedomProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -63,14 +63,11 @@ public class FreedomProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Identification
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
-        
+        position.setDeviceId(getDeviceId());
+
         // Validity
         position.setValid(true);
 
diff --git a/src/org/traccar/protocol/GalileoProtocolDecoder.java b/src/org/traccar/protocol/GalileoProtocolDecoder.java
index 0fa881949..99b745175 100644
--- a/src/org/traccar/protocol/GalileoProtocolDecoder.java
+++ b/src/org/traccar/protocol/GalileoProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class GalileoProtocolDecoder extends BaseProtocolDecoder {
 
-    public GalileoProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public GalileoProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final int TAG_IMEI = 0x03;
@@ -77,9 +77,7 @@ public class GalileoProtocolDecoder extends BaseProtocolDecoder {
             channel.write(reply);
         }
     }
-    
-    private Long deviceId;
-    
+
     @Override
     protected Object decode(
             ChannelHandlerContext ctx, Channel channel, Object msg)
@@ -113,11 +111,7 @@ public class GalileoProtocolDecoder extends BaseProtocolDecoder {
                 case TAG_IMEI:
                     String imei = buf.toString(buf.readerIndex(), 15, Charset.defaultCharset());
                     buf.skipBytes(imei.length());
-                    try {
-                        deviceId = getDataManager().getDeviceByImei(imei).getId();
-                    } catch(Exception error) {
-                        Log.warning("Unknown device - " + imei);
-                    }
+                    identify(imei);
                     break;
 
                 case TAG_DATE:
@@ -165,7 +159,7 @@ public class GalileoProtocolDecoder extends BaseProtocolDecoder {
         position.setExtendedInfo(extendedInfo.toString());
         positions.add(position);
         
-        if (deviceId == null) {
+        if (!hasDeviceId()) {
             Log.warning("Unknown device");
             return null;
         }
@@ -175,7 +169,7 @@ public class GalileoProtocolDecoder extends BaseProtocolDecoder {
         for (Iterator<Position> i = positions.iterator(); i.hasNext(); ) {
             Position p = i.next();
 
-            p.setDeviceId(deviceId);
+            p.setDeviceId(getDeviceId());
 
             if (p.getAltitude() == null) {
                 p.setAltitude(0.0);
diff --git a/src/org/traccar/protocol/GatorProtocolDecoder.java b/src/org/traccar/protocol/GatorProtocolDecoder.java
index 5bc205214..33b8c501c 100644
--- a/src/org/traccar/protocol/GatorProtocolDecoder.java
+++ b/src/org/traccar/protocol/GatorProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class GatorProtocolDecoder extends BaseProtocolDecoder {
 
-    public GatorProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public GatorProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final int PACKET_HEARTBEAT = 0x21;
@@ -75,12 +75,11 @@ public class GatorProtocolDecoder extends BaseProtocolDecoder {
             ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
 
             // Identification
-            try {
-                position.setDeviceId(getDataManager().getDeviceByImei(id).getId());
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + id);
+            if (!identify(id)) {
+                return null;
             }
-            
+            position.setDeviceId(getDeviceId());
+
             // Date and time
             Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
             time.clear();
diff --git a/src/org/traccar/protocol/Gl100ProtocolDecoder.java b/src/org/traccar/protocol/Gl100ProtocolDecoder.java
index fb1e42cce..fb64d8dda 100644
--- a/src/org/traccar/protocol/Gl100ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Gl100ProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class Gl100ProtocolDecoder extends BaseProtocolDecoder {
 
-    public Gl100ProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public Gl100ProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -82,13 +82,10 @@ public class Gl100ProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Get device by IMEI
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Validity
         position.setValid(Integer.valueOf(parser.group(index++)) == 0);
diff --git a/src/org/traccar/protocol/Gl200ProtocolDecoder.java b/src/org/traccar/protocol/Gl200ProtocolDecoder.java
index 1c20c5cc1..969be7611 100644
--- a/src/org/traccar/protocol/Gl200ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Gl200ProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class Gl200ProtocolDecoder extends BaseProtocolDecoder {
 
-    public Gl200ProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public Gl200ProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -78,13 +78,10 @@ public class Gl200ProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Get device by IMEI
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Validity
         position.setValid(Integer.valueOf(parser.group(index++)) < 20);
diff --git a/src/org/traccar/protocol/GlobalSatProtocolDecoder.java b/src/org/traccar/protocol/GlobalSatProtocolDecoder.java
index fd0c04bb4..1a0132c4a 100644
--- a/src/org/traccar/protocol/GlobalSatProtocolDecoder.java
+++ b/src/org/traccar/protocol/GlobalSatProtocolDecoder.java
@@ -25,6 +25,7 @@ import org.jboss.netty.channel.Channel;
 import org.jboss.netty.channel.ChannelHandlerContext;
 
 import org.traccar.BaseProtocolDecoder;
+import org.traccar.Context;
 import org.traccar.database.DataManager;
 import org.traccar.helper.Log;
 import org.traccar.model.ExtendedInfoFormatter;
@@ -36,9 +37,10 @@ public class GlobalSatProtocolDecoder extends BaseProtocolDecoder {
     private String format0 = "TSPRXAB27GHKLMnaicz*U!";
     private String format1 = "SARY*U!";
 
-    public GlobalSatProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public GlobalSatProtocolDecoder(String protocol) {
+        super(protocol);
 
+        Properties properties = Context.getProps();
         if (properties != null) {
             if (properties.containsKey(protocol + ".format0")) {
                 format0 = properties.getProperty(protocol + ".format0");
@@ -97,12 +99,10 @@ public class GlobalSatProtocolDecoder extends BaseProtocolDecoder {
 
             switch(format.charAt(formatIndex)) {
                 case 'S':
-                    try {
-                        position.setDeviceId(getDataManager().getDeviceByImei(value).getId());
-                    } catch(Exception error) {
-                        Log.warning("Unknown device - " + value);
+                    if (!identify(value)) {
                         return null;
                     }
+                    position.setDeviceId(getDeviceId());
                     break;
                 case 'A':
                     if (value.isEmpty()) {
@@ -215,13 +215,10 @@ public class GlobalSatProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Identification
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Validity
         position.setValid(parser.group(index++).compareTo("1") != 0);
diff --git a/src/org/traccar/protocol/GoSafeProtocolDecoder.java b/src/org/traccar/protocol/GoSafeProtocolDecoder.java
index 65f058bb6..3d981bb60 100644
--- a/src/org/traccar/protocol/GoSafeProtocolDecoder.java
+++ b/src/org/traccar/protocol/GoSafeProtocolDecoder.java
@@ -33,8 +33,8 @@ import org.traccar.model.Position;
 
 public class GoSafeProtocolDecoder extends BaseProtocolDecoder {
 
-    public GoSafeProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public GoSafeProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -73,14 +73,11 @@ public class GoSafeProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Get device by IMEI
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
-        
+        position.setDeviceId(getDeviceId());
+
         // Date
         Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
         time.clear();
diff --git a/src/org/traccar/protocol/GotopProtocolDecoder.java b/src/org/traccar/protocol/GotopProtocolDecoder.java
index 2e49a5dd0..80196c04a 100644
--- a/src/org/traccar/protocol/GotopProtocolDecoder.java
+++ b/src/org/traccar/protocol/GotopProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class GotopProtocolDecoder extends BaseProtocolDecoder {
 
-    public GotopProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public GotopProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -67,13 +67,10 @@ public class GotopProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Get device by IMEI
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Validity
         position.setValid(parser.group(index++).compareTo("A") == 0);
diff --git a/src/org/traccar/protocol/Gps103ProtocolDecoder.java b/src/org/traccar/protocol/Gps103ProtocolDecoder.java
index 0d8257e55..b99507ffb 100644
--- a/src/org/traccar/protocol/Gps103ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Gps103ProtocolDecoder.java
@@ -33,8 +33,8 @@ import org.traccar.model.Position;
 
 public class Gps103ProtocolDecoder extends BaseProtocolDecoder {
 
-    public Gps103ProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public Gps103ProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -99,13 +99,10 @@ public class Gps103ProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Get device by IMEI
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Alarm message
         extendedInfo.set("alarm", parser.group(index++));
diff --git a/src/org/traccar/protocol/GpsGateProtocolDecoder.java b/src/org/traccar/protocol/GpsGateProtocolDecoder.java
index 80e06c911..cb26d3a61 100644
--- a/src/org/traccar/protocol/GpsGateProtocolDecoder.java
+++ b/src/org/traccar/protocol/GpsGateProtocolDecoder.java
@@ -33,15 +33,10 @@ import org.traccar.model.Position;
 
 public class GpsGateProtocolDecoder extends BaseProtocolDecoder {
 
-    private Long deviceId;
-
-    public GpsGateProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public GpsGateProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
-    /**
-     * Regular expressions pattern
-     */
     private static final Pattern pattern = Pattern.compile(
             "\\$GPRMC," +
             "(\\d{2})(\\d{2})(\\d{2})\\.?(\\d+)?," + // Time (HHMMSS.SSS)
@@ -76,11 +71,11 @@ public class GpsGateProtocolDecoder extends BaseProtocolDecoder {
                 int endIndex = sentence.indexOf(',', beginIndex);
                 if (endIndex != -1) {
                     String imei = sentence.substring(beginIndex, endIndex);
-                    try {
-                        deviceId = getDataManager().getDeviceByImei(imei).getId();
-                        send(channel, "$FRSES," + channel.getId());
-                    } catch(Exception error) {
-                        Log.warning("Unknown device - " + imei);
+                    if (identify(imei)) {
+                        if (channel != null) {
+                            send(channel, "$FRSES," + channel.getId());
+                        }
+                    } else {
                         send(channel, "$FRERR,AuthError,Unknown device");
                     }
                 } else {
@@ -97,7 +92,7 @@ public class GpsGateProtocolDecoder extends BaseProtocolDecoder {
         }
 
         // Process data
-        else if (sentence.startsWith("$GPRMC,") && deviceId != null) {
+        else if (sentence.startsWith("$GPRMC,") && hasDeviceId()) {
 
             // Parse message
             Matcher parser = pattern.matcher(sentence);
@@ -108,7 +103,7 @@ public class GpsGateProtocolDecoder extends BaseProtocolDecoder {
             // Create new position
             Position position = new Position();
             ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
-            position.setDeviceId(deviceId);
+            position.setDeviceId(getDeviceId());
 
             Integer index = 1;
 
diff --git a/src/org/traccar/protocol/Gt02ProtocolDecoder.java b/src/org/traccar/protocol/Gt02ProtocolDecoder.java
index 3857766c7..bab03d13f 100644
--- a/src/org/traccar/protocol/Gt02ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Gt02ProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class Gt02ProtocolDecoder extends BaseProtocolDecoder {
 
-    public Gt02ProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public Gt02ProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private String readImei(ChannelBuffer buf) {
@@ -84,12 +84,10 @@ public class Gt02ProtocolDecoder extends BaseProtocolDecoder {
             extendedInfo.set("index", index);
 
             // Get device id
-            try {
-                position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + imei);
+            if (!identify(imei)) {
                 return null;
             }
+            position.setDeviceId(getDeviceId());
 
             // Date and time
             Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
diff --git a/src/org/traccar/protocol/Gt06ProtocolDecoder.java b/src/org/traccar/protocol/Gt06ProtocolDecoder.java
index 1d81bb351..e94a7238b 100644
--- a/src/org/traccar/protocol/Gt06ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Gt06ProtocolDecoder.java
@@ -20,6 +20,7 @@ import org.jboss.netty.buffer.ChannelBuffers;
 import org.jboss.netty.channel.Channel;
 import org.jboss.netty.channel.ChannelHandlerContext;
 import org.traccar.BaseProtocolDecoder;
+import org.traccar.Context;
 import org.traccar.database.DataManager;
 import org.traccar.helper.Crc;
 import org.traccar.helper.Log;
@@ -32,19 +33,16 @@ import java.util.TimeZone;
 
 public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
 
-    private Long deviceId;
     private boolean forceTimeZone = false;
     private final TimeZone timeZone = TimeZone.getTimeZone("UTC");
 
-    public Gt06ProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
-        
-        if (properties != null) {
-            if (properties.containsKey(protocol + ".timezone")) {
-                forceTimeZone = true;
-                timeZone.setRawOffset(
-                        Integer.valueOf(properties.getProperty(protocol + ".timezone")) * 1000);
-            }
+    public Gt06ProtocolDecoder(String protocol) {
+        super(protocol);
+
+        Properties properties = Context.getProps();
+        if (properties != null && properties.containsKey(protocol + ".timezone")) {
+            forceTimeZone = true;
+            timeZone.setRawOffset(Integer.valueOf(properties.getProperty(protocol + ".timezone")) * 1000);
         }
     }
 
@@ -126,16 +124,13 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
                     timeZone.setRawOffset(offset);
                 }
             }
-            
-            try {
-                deviceId = getDataManager().getDeviceByImei(imei).getId();
+
+            if (identify(imei)) {
                 buf.skipBytes(buf.readableBytes() - 6);
                 sendResponse(channel, type, buf.readUnsignedShort());
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + imei);
             }
-            
-        } else if (deviceId != null && (
+
+        } else if (hasDeviceId() && (
                 type == MSG_GPS ||
                 type == MSG_GPS_LBS_1 ||
                 type == MSG_GPS_LBS_2 ||
@@ -147,7 +142,7 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
 
             // Create new position
             Position position = new Position();
-            position.setDeviceId(deviceId);
+            position.setDeviceId(getDeviceId());
             ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
 
             // Date and time
diff --git a/src/org/traccar/protocol/H02ProtocolDecoder.java b/src/org/traccar/protocol/H02ProtocolDecoder.java
index 84ddaf895..51d1ed8d0 100644
--- a/src/org/traccar/protocol/H02ProtocolDecoder.java
+++ b/src/org/traccar/protocol/H02ProtocolDecoder.java
@@ -35,8 +35,8 @@ import org.traccar.model.Position;
 
 public class H02ProtocolDecoder extends BaseProtocolDecoder {
 
-    public H02ProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public H02ProtocolDecoder(String protocol) {
+        super(protocol);
     }
     
     private static double readCoordinate(ChannelBuffer buf, boolean lon) {
@@ -67,14 +67,11 @@ public class H02ProtocolDecoder extends BaseProtocolDecoder {
         buf.readByte(); // marker
 
         // Identification
-        String id = ChannelBufferTools.readHexString(buf, 10);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(id).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + id);
+        if (!identify(ChannelBufferTools.readHexString(buf, 10))) {
             return null;
         }
-        
+        position.setDeviceId(getDeviceId());
+
         // Time
         Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
         time.clear();
@@ -141,13 +138,10 @@ public class H02ProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Get device by IMEI
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Time
         Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
diff --git a/src/org/traccar/protocol/HaicomProtocolDecoder.java b/src/org/traccar/protocol/HaicomProtocolDecoder.java
index 078ee9ae6..ae070fd84 100644
--- a/src/org/traccar/protocol/HaicomProtocolDecoder.java
+++ b/src/org/traccar/protocol/HaicomProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class HaicomProtocolDecoder extends BaseProtocolDecoder {
 
-    public HaicomProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public HaicomProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -75,13 +75,10 @@ public class HaicomProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Get device by IMEI
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Firmware version
         extendedInfo.set("version", parser.group(index++));
diff --git a/src/org/traccar/protocol/IntellitracProtocolDecoder.java b/src/org/traccar/protocol/IntellitracProtocolDecoder.java
index fa1837e50..3b03a6b2d 100644
--- a/src/org/traccar/protocol/IntellitracProtocolDecoder.java
+++ b/src/org/traccar/protocol/IntellitracProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class IntellitracProtocolDecoder extends BaseProtocolDecoder {
 
-    public IntellitracProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public IntellitracProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -83,13 +83,10 @@ public class IntellitracProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Detect device
-        String id = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(id).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + id);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
         
         // Date and time
         Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
diff --git a/src/org/traccar/protocol/Jt600ProtocolDecoder.java b/src/org/traccar/protocol/Jt600ProtocolDecoder.java
index 197b4103a..80c584d21 100644
--- a/src/org/traccar/protocol/Jt600ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Jt600ProtocolDecoder.java
@@ -35,8 +35,8 @@ import org.traccar.model.Position;
 
 public class Jt600ProtocolDecoder extends BaseProtocolDecoder {
 
-    public Jt600ProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public Jt600ProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private Position decodeNormalMessage(ChannelBuffer buf) throws Exception {
@@ -48,12 +48,10 @@ public class Jt600ProtocolDecoder extends BaseProtocolDecoder {
 
         // Get device by identifier
         String id = Long.valueOf(ChannelBufferTools.readHexString(buf, 10)).toString();
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(id).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + id);
-            //return null;
+        if (!identify(id)) {
+            return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Protocol and type
         int version = ChannelBufferTools.readHexInteger(buf, 1);
@@ -166,13 +164,10 @@ public class Jt600ProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Get device by identifier
-        String id = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(id).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + id);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Longitude
         Double longitude = Double.valueOf(parser.group(index++));
diff --git a/src/org/traccar/protocol/KhdProtocolDecoder.java b/src/org/traccar/protocol/KhdProtocolDecoder.java
index 022def9eb..ed974d8ca 100644
--- a/src/org/traccar/protocol/KhdProtocolDecoder.java
+++ b/src/org/traccar/protocol/KhdProtocolDecoder.java
@@ -34,8 +34,8 @@ import org.traccar.model.Position;
 
 public class KhdProtocolDecoder extends BaseProtocolDecoder {
 
-    public KhdProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public KhdProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private String readSerialNumber(ChannelBuffer buf) {
@@ -79,13 +79,11 @@ public class KhdProtocolDecoder extends BaseProtocolDecoder {
             ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
 
             // Device identification
-            String id = readSerialNumber(buf);
-            try {
-                position.setDeviceId(getDataManager().getDeviceByImei(id).getId());
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + id);
+            if (!identify(readSerialNumber(buf))) {
+                return null;
             }
-            
+            position.setDeviceId(getDeviceId());
+
             // Date and time
             Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
             time.clear();
diff --git a/src/org/traccar/protocol/LaipacProtocolDecoder.java b/src/org/traccar/protocol/LaipacProtocolDecoder.java
index f95109b80..b868887ec 100644
--- a/src/org/traccar/protocol/LaipacProtocolDecoder.java
+++ b/src/org/traccar/protocol/LaipacProtocolDecoder.java
@@ -33,8 +33,8 @@ import org.traccar.model.Position;
 
 public class LaipacProtocolDecoder extends BaseProtocolDecoder {
 
-    public LaipacProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public LaipacProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -78,12 +78,10 @@ public class LaipacProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Identification
-        String id = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(id).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + id);
+        if (!identify(parser.group(index++))) {
+            return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Time
         Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
diff --git a/src/org/traccar/protocol/M2mProtocolDecoder.java b/src/org/traccar/protocol/M2mProtocolDecoder.java
index 46442fb4f..0daa07422 100644
--- a/src/org/traccar/protocol/M2mProtocolDecoder.java
+++ b/src/org/traccar/protocol/M2mProtocolDecoder.java
@@ -31,12 +31,11 @@ import org.traccar.model.Position;
 
 public class M2mProtocolDecoder extends BaseProtocolDecoder {
 
-    public M2mProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public M2mProtocolDecoder(String protocol) {
+        super(protocol);
     }
     
     private boolean firstPacket = true;
-    private Long deviceId;
 
     @Override
     protected Object decode(
@@ -68,18 +67,14 @@ public class M2mProtocolDecoder extends BaseProtocolDecoder {
             }
 
             // Identification
-            try {
-                deviceId = getDataManager().getDeviceByImei(imei.toString()).getId();
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + imei);
-            }
-            
-        } else if (deviceId != null) {
+            identify(imei.toString());
+
+        } else if (hasDeviceId()) {
             
             // Create new position
             Position position = new Position();
             ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
-            position.setDeviceId(deviceId);
+            position.setDeviceId(getDeviceId());
 
             // Date and time
             Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
diff --git a/src/org/traccar/protocol/ManPowerProtocolDecoder.java b/src/org/traccar/protocol/ManPowerProtocolDecoder.java
index 449a1b532..dea190715 100644
--- a/src/org/traccar/protocol/ManPowerProtocolDecoder.java
+++ b/src/org/traccar/protocol/ManPowerProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class ManPowerProtocolDecoder extends BaseProtocolDecoder {
 
-    public ManPowerProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public ManPowerProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     static private Pattern pattern = Pattern.compile(
@@ -72,13 +72,10 @@ public class ManPowerProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Get device by IMEI
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Alarm message
         extendedInfo.set("status", parser.group(index++));
@@ -95,7 +92,7 @@ public class ManPowerProtocolDecoder extends BaseProtocolDecoder {
         position.setTime(time.getTime());
 
         // Validity
-        position.setValid(parser.group(index++).compareTo("A") == 0 ? true : false);
+        position.setValid(parser.group(index++).compareTo("A") == 0);
 
         // Latitude
         Double latitude = Double.valueOf(parser.group(index++));
diff --git a/src/org/traccar/protocol/MaxonProtocolDecoder.java b/src/org/traccar/protocol/MaxonProtocolDecoder.java
index eb1e43885..cd86e5e65 100644
--- a/src/org/traccar/protocol/MaxonProtocolDecoder.java
+++ b/src/org/traccar/protocol/MaxonProtocolDecoder.java
@@ -38,21 +38,12 @@ import org.traccar.model.Position;
  */
 public class MaxonProtocolDecoder extends BaseProtocolDecoder {
 
-    /**
-     * Device ID
-     */
     private Position position = null;
 
-    /**
-     * Initialize
-     */
-    public MaxonProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public MaxonProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
-    /**
-     * Regular expressions pattern
-     */
     static private Pattern pattern = Pattern.compile(
             "\\$GPRMC," +
             "(\\d{2})(\\d{2})(\\d{2})\\.(\\d{2})," + // Time (HHMMSS.SSS)
@@ -66,12 +57,8 @@ public class MaxonProtocolDecoder extends BaseProtocolDecoder {
             "(\\d{2})(\\d{2})(\\d{2})" +   // Date (DDMMYY)
             ".+");                         // Other (Checksumm)
 
-    static private Pattern gpfidPattern = Pattern.compile(
-            "\\$GPFID,(\\d+)$");
+    static private Pattern gpfidPattern = Pattern.compile("\\$GPFID,(\\d+)$");
 
-    /**
-     * Decode message"
-     */
     protected Object decode(
             ChannelHandlerContext ctx, Channel channel, Object msg)
             throws Exception {
@@ -102,7 +89,7 @@ public class MaxonProtocolDecoder extends BaseProtocolDecoder {
             index += 1; // Skip milliseconds
 
             // Validity
-            position.setValid(parser.group(index++).compareTo("A") == 0 ? true : false);
+            position.setValid(parser.group(index++).compareTo("A") == 0);
 
             // Latitude
             Double latitude = Double.valueOf(parser.group(index++));
@@ -145,13 +132,10 @@ public class MaxonProtocolDecoder extends BaseProtocolDecoder {
             Matcher parser = gpfidPattern.matcher(sentence);
 
             if (parser.matches()) {
-                String imei = parser.group(1);
-                try {
-                    position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-                } catch(Exception error) {
-                    Log.warning("Unknown device - " + imei);
+                if (!identify(parser.group(1))) {
                     return null;
                 }
+                position.setDeviceId(getDeviceId());
                 return position;
             }
         }
diff --git a/src/org/traccar/protocol/MegastekProtocolDecoder.java b/src/org/traccar/protocol/MegastekProtocolDecoder.java
index 2eed12fce..4a621245a 100644
--- a/src/org/traccar/protocol/MegastekProtocolDecoder.java
+++ b/src/org/traccar/protocol/MegastekProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class MegastekProtocolDecoder extends BaseProtocolDecoder {
 
-    public MegastekProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public MegastekProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern patternGPRMC = Pattern.compile(
@@ -49,7 +49,6 @@ public class MegastekProtocolDecoder extends BaseProtocolDecoder {
             "(\\d{2})(\\d{2})(\\d{2})" +   // Date (DDMMYY)
             "[^\\*]+\\*[0-9a-fA-F]{2}");   // Checksum
 
-    //F,,imei:123456789012345,0/6,,Battery=100%,,0,,,5856,78A3;24
     private static final Pattern patternSimple = Pattern.compile(
             "[FL]," +                      // Flag
             "([^,]*)," +                   // Alarm
@@ -200,17 +199,12 @@ public class MegastekProtocolDecoder extends BaseProtocolDecoder {
             extendedInfo.set("alarm", parser.group(index++));
 
             // IMEI
-            String imei = parser.group(index++);
-            try {
-                position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-            } catch(Exception firstError) {
-                try {
-                    position.setDeviceId(getDataManager().getDeviceByImei(id).getId());
-                } catch(Exception secondError) {
-                    Log.warning("Unknown device - " + imei + " (id - " + id + ")");
+            if (!identify(parser.group(index++), false)) {
+                if (!identify(id)) {
                     return null;
                 }
             }
+            position.setDeviceId(getDeviceId());
 
             // Satellites
             extendedInfo.set("satellites", parser.group(index++));
@@ -248,13 +242,11 @@ public class MegastekProtocolDecoder extends BaseProtocolDecoder {
 
             // Altitude
             position.setAltitude(0.0);
-            
-            try {
-                position.setDeviceId(getDataManager().getDeviceByImei(id).getId());
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + id);
+
+            if (!identify(id)) {
                 return null;
             }
+            position.setDeviceId(getDeviceId());
 
             extendedInfo.set("mcc", parser.group(index++));
             extendedInfo.set("mnc", parser.group(index++));
diff --git a/src/org/traccar/protocol/MeiligaoProtocolDecoder.java b/src/org/traccar/protocol/MeiligaoProtocolDecoder.java
index 9c1f5bee9..547821c69 100644
--- a/src/org/traccar/protocol/MeiligaoProtocolDecoder.java
+++ b/src/org/traccar/protocol/MeiligaoProtocolDecoder.java
@@ -29,6 +29,7 @@ import org.jboss.netty.channel.Channel;
 import org.jboss.netty.channel.ChannelHandlerContext;
 
 import org.traccar.BaseProtocolDecoder;
+import org.traccar.Context;
 import org.traccar.database.DataManager;
 import org.traccar.helper.Crc;
 import org.traccar.helper.Log;
@@ -37,8 +38,8 @@ import org.traccar.model.Position;
 
 public class MeiligaoProtocolDecoder extends BaseProtocolDecoder {
 
-    public MeiligaoProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public MeiligaoProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -117,7 +118,7 @@ public class MeiligaoProtocolDecoder extends BaseProtocolDecoder {
     }
     
     private String getMeiligaoServer(Channel channel) {
-        Properties p = getProperties();
+        Properties p = Context.getProps();
         
         if (p != null && p.containsKey(getProtocol() + ".server")) {
             return p.getProperty(getProtocol() + ".server");
@@ -179,13 +180,10 @@ public class MeiligaoProtocolDecoder extends BaseProtocolDecoder {
         }
 
         // Get device by id
-        String imei = getImei(id);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(getImei(id))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Parse message
         String sentence = buf.toString(
diff --git a/src/org/traccar/protocol/MeitrackProtocolDecoder.java b/src/org/traccar/protocol/MeitrackProtocolDecoder.java
index cdeef155b..e213b7ddb 100644
--- a/src/org/traccar/protocol/MeitrackProtocolDecoder.java
+++ b/src/org/traccar/protocol/MeitrackProtocolDecoder.java
@@ -38,8 +38,8 @@ import org.traccar.model.Position;
 
 public class MeitrackProtocolDecoder extends BaseProtocolDecoder {
 
-    public MeitrackProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public MeitrackProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -91,13 +91,10 @@ public class MeitrackProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Identification
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Event
         int event = Integer.valueOf(parser.group(index++));
@@ -191,22 +188,18 @@ public class MeitrackProtocolDecoder extends BaseProtocolDecoder {
         int index = ChannelBufferTools.find(buf, 0, buf.readableBytes(), ",");
         
         // Identification
-        long deviceId;
         String imei = buf.toString(index + 1, 15, Charset.defaultCharset());
-        try {
-            deviceId = getDataManager().getDeviceByImei(imei).getId();
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(imei)) {
             return null;
         }
-        
+
         buf.skipBytes(index + 1 + 15 + 1 + 3 + 1 + 2 + 2 + 4);
         
         while (buf.readableBytes() >= 0x34) {
             
             Position position = new Position();
             ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
-            position.setDeviceId(deviceId);
+            position.setDeviceId(getDeviceId());
             
             // Event
             extendedInfo.set("event", buf.readUnsignedByte());
diff --git a/src/org/traccar/protocol/MiniFinderProtocolDecoder.java b/src/org/traccar/protocol/MiniFinderProtocolDecoder.java
index 9a6c7396c..c37e44659 100644
--- a/src/org/traccar/protocol/MiniFinderProtocolDecoder.java
+++ b/src/org/traccar/protocol/MiniFinderProtocolDecoder.java
@@ -32,10 +32,8 @@ import org.traccar.model.Position;
 
 public class MiniFinderProtocolDecoder extends BaseProtocolDecoder {
 
-    private Long deviceId;
-
-    public MiniFinderProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public MiniFinderProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -62,16 +60,11 @@ public class MiniFinderProtocolDecoder extends BaseProtocolDecoder {
 
         // Identification
         if (sentence.startsWith("!1")) {
-            String imei = sentence.substring(3, sentence.length());
-            try {
-                deviceId = getDataManager().getDeviceByImei(imei).getId();
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + imei);
-            }
+            identify(sentence.substring(3, sentence.length()));
         }
 
         // Location
-        else if (sentence.startsWith("!D") && deviceId != null) {
+        else if (sentence.startsWith("!D") && hasDeviceId()) {
 
             // Parse message
             Matcher parser = pattern.matcher(sentence);
@@ -82,7 +75,7 @@ public class MiniFinderProtocolDecoder extends BaseProtocolDecoder {
             // Create new position
             Position position = new Position();
             ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
-            position.setDeviceId(deviceId);
+            position.setDeviceId(getDeviceId());
 
             Integer index = 1;
 
diff --git a/src/org/traccar/protocol/Mta6ProtocolDecoder.java b/src/org/traccar/protocol/Mta6ProtocolDecoder.java
index d8d1b9f98..f09cf32f1 100644
--- a/src/org/traccar/protocol/Mta6ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Mta6ProtocolDecoder.java
@@ -44,8 +44,8 @@ public class Mta6ProtocolDecoder extends BaseProtocolDecoder {
     
     private boolean simple;
 
-    public Mta6ProtocolDecoder(DataManager dataManager, String protocol, Properties properties, boolean simple) {
-        super(dataManager, protocol, properties);
+    public Mta6ProtocolDecoder(String protocol, boolean simple) {
+        super(protocol);
         this.simple = simple;
     }
 
@@ -121,7 +121,7 @@ public class Mta6ProtocolDecoder extends BaseProtocolDecoder {
         
     }
 
-    private List<Position> parseFormatA(ChannelBuffer buf, long deviceId) {
+    private List<Position> parseFormatA(ChannelBuffer buf) {
         List<Position> positions = new LinkedList<Position>();
         
         FloatReader latitudeReader = new FloatReader();
@@ -131,7 +131,7 @@ public class Mta6ProtocolDecoder extends BaseProtocolDecoder {
         try {
             while (buf.readable()) {
                 Position position = new Position();
-                position.setDeviceId(deviceId);
+                position.setDeviceId(getDeviceId());
                 ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
 
                 short flags = buf.readUnsignedByte();
@@ -211,9 +211,9 @@ public class Mta6ProtocolDecoder extends BaseProtocolDecoder {
         return positions;
     }
 
-    private Position parseFormatA1(ChannelBuffer buf, long deviceId) {
+    private Position parseFormatA1(ChannelBuffer buf) {
         Position position = new Position();
-        position.setDeviceId(deviceId);
+        position.setDeviceId(getDeviceId());
         ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
 
         short flags = buf.readUnsignedByte();
@@ -303,11 +303,7 @@ public class Mta6ProtocolDecoder extends BaseProtocolDecoder {
         buf.skipBytes("id=".length());
         int index = ChannelBufferTools.find(buf, buf.readerIndex(), length, "&");
         String uniqueId = buf.toString(buf.readerIndex(), index - buf.readerIndex(), Charset.defaultCharset());
-        long deviceId;
-        try {
-            deviceId = getDataManager().getDeviceByImei(uniqueId).getId();
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + uniqueId);
+        if (!identify(uniqueId)) {
             return null;
         }
         buf.skipBytes(uniqueId.length());
@@ -330,9 +326,9 @@ public class Mta6ProtocolDecoder extends BaseProtocolDecoder {
         // Parse data
         if (packetId == 0x31 || packetId == 0x32 || packetId == 0x36) {
             if (simple) {
-                return parseFormatA1(buf, deviceId);
+                return parseFormatA1(buf);
             } else {
-                return parseFormatA(buf, deviceId);
+                return parseFormatA(buf);
             }
         } //else if (0x34 0x38 0x4F 0x59)
 
diff --git a/src/org/traccar/protocol/MtxProtocolDecoder.java b/src/org/traccar/protocol/MtxProtocolDecoder.java
index c552e3831..150e95e3b 100644
--- a/src/org/traccar/protocol/MtxProtocolDecoder.java
+++ b/src/org/traccar/protocol/MtxProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class MtxProtocolDecoder extends BaseProtocolDecoder {
 
-    public MtxProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public MtxProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -79,13 +79,10 @@ public class MtxProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Get device by IMEI
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
         
         // Date
         Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
diff --git a/src/org/traccar/protocol/NavigilProtocolDecoder.java b/src/org/traccar/protocol/NavigilProtocolDecoder.java
index eb9ad96d3..f12e15fb6 100644
--- a/src/org/traccar/protocol/NavigilProtocolDecoder.java
+++ b/src/org/traccar/protocol/NavigilProtocolDecoder.java
@@ -33,8 +33,8 @@ import org.traccar.model.Position;
 
 public class NavigilProtocolDecoder extends BaseProtocolDecoder {
 
-    public NavigilProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public NavigilProtocolDecoder(String protocol) {
+        super(protocol);
     }
     
     private static final int LEAP_SECONDS_DELTA = 25;
@@ -81,13 +81,13 @@ public class NavigilProtocolDecoder extends BaseProtocolDecoder {
         }
     }
     
-    private Position parseUnitReport(ChannelBuffer buf, long deviceId, int sequenceNumber) {
+    private Position parseUnitReport(ChannelBuffer buf, int sequenceNumber) {
         Position position = new Position();
         ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
 
         position.setValid(true);
         extendedInfo.set("index", sequenceNumber);
-        position.setDeviceId(deviceId);
+        position.setDeviceId(getDeviceId());
         
         buf.readUnsignedShort(); // report trigger
         buf.readUnsignedShort(); // flags
@@ -118,13 +118,13 @@ public class NavigilProtocolDecoder extends BaseProtocolDecoder {
         return position;
     }
     
-    private Position parseTg2Report(ChannelBuffer buf, long deviceId, int sequenceNumber) {
+    private Position parseTg2Report(ChannelBuffer buf, int sequenceNumber) {
         Position position = new Position();
         ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
 
         position.setValid(true);
         extendedInfo.set("index", sequenceNumber);
-        position.setDeviceId(deviceId);
+        position.setDeviceId(getDeviceId());
         
         buf.readUnsignedShort(); // report trigger
         buf.readUnsignedByte(); // reserved
@@ -157,12 +157,12 @@ public class NavigilProtocolDecoder extends BaseProtocolDecoder {
         return position;
     }
     
-    private Position parsePositionReport(ChannelBuffer buf, long deviceId, int sequenceNumber, long timestamp) {
+    private Position parsePositionReport(ChannelBuffer buf, int sequenceNumber, long timestamp) {
         Position position = new Position();
         ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
 
         extendedInfo.set("index", sequenceNumber);
-        position.setDeviceId(deviceId);
+        position.setDeviceId(getDeviceId());
         position.setTime(convertTimestamp(timestamp));
         
         position.setLatitude(buf.readMedium() * 0.00002);
@@ -181,12 +181,12 @@ public class NavigilProtocolDecoder extends BaseProtocolDecoder {
         return position;
     }
     
-    private Position parsePositionReport2(ChannelBuffer buf, long deviceId, int sequenceNumber, long timestamp) {
+    private Position parsePositionReport2(ChannelBuffer buf, int sequenceNumber, long timestamp) {
         Position position = new Position();
         ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
 
         extendedInfo.set("index", sequenceNumber);
-        position.setDeviceId(deviceId);
+        position.setDeviceId(getDeviceId());
         position.setTime(convertTimestamp(timestamp));
         
         position.setLatitude(buf.readInt() * 0.0000001);
@@ -208,12 +208,12 @@ public class NavigilProtocolDecoder extends BaseProtocolDecoder {
         return position;
     }
     
-    private Position parseSnapshot4(ChannelBuffer buf, long deviceId, int sequenceNumber) {
+    private Position parseSnapshot4(ChannelBuffer buf, int sequenceNumber) {
         Position position = new Position();
         ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
 
         extendedInfo.set("index", sequenceNumber);
-        position.setDeviceId(deviceId);
+        position.setDeviceId(getDeviceId());
 
         buf.readUnsignedByte(); // report trigger
         buf.readUnsignedByte(); // position fix source
@@ -249,12 +249,12 @@ public class NavigilProtocolDecoder extends BaseProtocolDecoder {
         return position;
     }
     
-    private Position parseTrackingData(ChannelBuffer buf, long deviceId, int sequenceNumber, long timestamp) {
+    private Position parseTrackingData(ChannelBuffer buf, int sequenceNumber, long timestamp) {
         Position position = new Position();
         ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
 
         extendedInfo.set("index", sequenceNumber);
-        position.setDeviceId(deviceId);
+        position.setDeviceId(getDeviceId());
         position.setTime(convertTimestamp(timestamp));
 
         buf.readUnsignedByte(); // tracking mode
@@ -296,12 +296,7 @@ public class NavigilProtocolDecoder extends BaseProtocolDecoder {
         buf.readUnsignedShort(); // checksum
         
         // Get device identifier
-        long deviceId;
-        String navigilDeviceId = String.valueOf(buf.readUnsignedInt());
-        try {
-            deviceId = getDataManager().getDeviceByImei(navigilDeviceId).getId();
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + navigilDeviceId);
+        if (!identify(String.valueOf(buf.readUnsignedInt()))) {
             return null;
         }
 
@@ -315,17 +310,17 @@ public class NavigilProtocolDecoder extends BaseProtocolDecoder {
         // Parse messages
         switch (messageId) {
             case MESSAGE_UNIT_REPORT:
-                return parseUnitReport(buf, deviceId, sequenceNumber);
+                return parseUnitReport(buf, sequenceNumber);
             case MESSAGE_TG2_REPORT:
-                return parseTg2Report(buf, deviceId, sequenceNumber);
+                return parseTg2Report(buf, sequenceNumber);
             case MESSAGE_POSITION_REPORT:
-                return parsePositionReport(buf, deviceId, sequenceNumber, timestamp);
+                return parsePositionReport(buf, sequenceNumber, timestamp);
             case MESSAGE_POSITION_REPORT_2:
-                return parsePositionReport2(buf, deviceId, sequenceNumber, timestamp);
+                return parsePositionReport2(buf, sequenceNumber, timestamp);
             case MESSAGE_SNAPSHOT4:
-                return parseSnapshot4(buf, deviceId, sequenceNumber);
+                return parseSnapshot4(buf, sequenceNumber);
             case MESSAGE_TRACKING_DATA:
-                return parseTrackingData(buf, deviceId, sequenceNumber, timestamp);
+                return parseTrackingData(buf, sequenceNumber, timestamp);
         }
         
         return null;
diff --git a/src/org/traccar/protocol/NavisProtocolDecoder.java b/src/org/traccar/protocol/NavisProtocolDecoder.java
index 4646d215f..8a5afc17f 100644
--- a/src/org/traccar/protocol/NavisProtocolDecoder.java
+++ b/src/org/traccar/protocol/NavisProtocolDecoder.java
@@ -37,15 +37,12 @@ import org.traccar.model.Position;
 public class NavisProtocolDecoder extends BaseProtocolDecoder {
 
     private String prefix;
-    private long deviceId, serverId;
+    private long deviceUniqueId, serverId;
 
     private static final Charset charset = Charset.defaultCharset();
 
-    private String imei;
-    private Long databaseDeviceId;
-
-    public NavisProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public NavisProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     // Format types
@@ -88,7 +85,7 @@ public class NavisProtocolDecoder extends BaseProtocolDecoder {
         Position position = new Position();
         ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
 
-        position.setDeviceId(databaseDeviceId);
+        position.setDeviceId(getDeviceId());
         position.setAltitude(0.0);
 
         // Format type
@@ -262,12 +259,8 @@ public class NavisProtocolDecoder extends BaseProtocolDecoder {
 
     private Object processHandshake(Channel channel, ChannelBuffer buf) {
         buf.readByte(); // semicolon symbol
-        imei = buf.toString(Charset.defaultCharset());
-        try {
-            databaseDeviceId = getDataManager().getDeviceByImei(imei).getId();
+        if (identify(buf.toString(Charset.defaultCharset()))) {
             sendReply(channel, ChannelBuffers.copiedBuffer(ByteOrder.LITTLE_ENDIAN, "*<S", charset));
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
         }
         return null;
     }
@@ -283,7 +276,7 @@ public class NavisProtocolDecoder extends BaseProtocolDecoder {
     private void sendReply(Channel channel, ChannelBuffer data) {
         ChannelBuffer header = ChannelBuffers.directBuffer(ByteOrder.LITTLE_ENDIAN, 16);
         header.writeBytes(ChannelBuffers.copiedBuffer(ByteOrder.LITTLE_ENDIAN, prefix, charset));
-        header.writeInt((int) deviceId);
+        header.writeInt((int) deviceUniqueId);
         header.writeInt((int) serverId);
         header.writeShort(data.readableBytes());
         header.writeByte(checksum(data));
@@ -305,7 +298,7 @@ public class NavisProtocolDecoder extends BaseProtocolDecoder {
         prefix = buf.toString(buf.readerIndex(), 4, charset);
         buf.skipBytes(prefix.length()); // prefix @NTC by default
         serverId = buf.readUnsignedInt();
-        deviceId = buf.readUnsignedInt();
+        deviceUniqueId = buf.readUnsignedInt();
         int length = buf.readUnsignedShort();
         buf.skipBytes(2); // header and data XOR checksum
 
diff --git a/src/org/traccar/protocol/NoranProtocolDecoder.java b/src/org/traccar/protocol/NoranProtocolDecoder.java
index b6fa93607..bc807711d 100644
--- a/src/org/traccar/protocol/NoranProtocolDecoder.java
+++ b/src/org/traccar/protocol/NoranProtocolDecoder.java
@@ -35,8 +35,8 @@ import org.traccar.model.Position;
 
 public class NoranProtocolDecoder extends BaseProtocolDecoder {
 
-    public NoranProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public NoranProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final int MSG_UPLOAD_POSITION = 0x0008;
@@ -111,13 +111,11 @@ public class NoranProtocolDecoder extends BaseProtocolDecoder {
 
             // Identification
             String id = buf.readBytes(11).toString(Charset.defaultCharset()).replaceAll("[^\\p{Print}]", "");
-            try {
-                position.setDeviceId(getDataManager().getDeviceByImei(id).getId());
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + id);
+            if (!identify(id)) {
                 return null;
             }
-            
+            position.setDeviceId(getDeviceId());
+
             // IO status
             extendedInfo.set("io", buf.readUnsignedByte());
             
diff --git a/src/org/traccar/protocol/OrionProtocolDecoder.java b/src/org/traccar/protocol/OrionProtocolDecoder.java
index f20bb6d72..3b4b598b1 100644
--- a/src/org/traccar/protocol/OrionProtocolDecoder.java
+++ b/src/org/traccar/protocol/OrionProtocolDecoder.java
@@ -34,8 +34,8 @@ import org.traccar.model.Position;
 
 public class OrionProtocolDecoder extends BaseProtocolDecoder {
 
-    public OrionProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public OrionProtocolDecoder(String protocol) {
+        super(protocol);
     }
     
     private static final int TYPE_USERLOG = 0;
@@ -74,23 +74,18 @@ public class OrionProtocolDecoder extends BaseProtocolDecoder {
             if ((header & 0x40) != 0) {
                 sendResponse(channel, buf);
             }
-            
-            String id = String.valueOf(buf.readUnsignedInt());
-            long deviceId;
-            try {
-                deviceId = getDataManager().getDeviceByImei(id).getId();
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + id);
+
+            if (!identify(String.valueOf(buf.readUnsignedInt()))) {
                 return null;
             }
-            
+
             List<Position> positions = new LinkedList<Position>();
             
             for (int i = 0; i < (header & 0x0f); i++) {
                 
                 // Create new position
                 Position position = new Position();
-                position.setDeviceId(deviceId);
+                position.setDeviceId(getDeviceId());
                 ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
                 
                 extendedInfo.set("event", buf.readUnsignedByte());
diff --git a/src/org/traccar/protocol/OsmAndProtocolDecoder.java b/src/org/traccar/protocol/OsmAndProtocolDecoder.java
index f773a4633..85cf1219c 100644
--- a/src/org/traccar/protocol/OsmAndProtocolDecoder.java
+++ b/src/org/traccar/protocol/OsmAndProtocolDecoder.java
@@ -41,8 +41,8 @@ import org.traccar.model.Position;
 
 public class OsmAndProtocolDecoder extends BaseProtocolDecoder {
     
-    public OsmAndProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public OsmAndProtocolDecoder(String protocol) {
+        super(protocol);
     }
     
     @Override
@@ -65,12 +65,10 @@ public class OsmAndProtocolDecoder extends BaseProtocolDecoder {
 
         // Identification
         String id = params.get(params.containsKey("id") ? "id" : "deviceid").get(0);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(id).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + id);
+        if (!identify(id)) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Decode position
         position.setValid(true);
diff --git a/src/org/traccar/protocol/PiligrimProtocolDecoder.java b/src/org/traccar/protocol/PiligrimProtocolDecoder.java
index 02c86152d..1c0faef37 100644
--- a/src/org/traccar/protocol/PiligrimProtocolDecoder.java
+++ b/src/org/traccar/protocol/PiligrimProtocolDecoder.java
@@ -42,8 +42,8 @@ import org.traccar.model.Position;
 
 public class PiligrimProtocolDecoder extends BaseProtocolDecoder {
     
-    public PiligrimProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public PiligrimProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private void sendResponse(Channel channel, String message) {
@@ -85,13 +85,8 @@ public class PiligrimProtocolDecoder extends BaseProtocolDecoder {
             sendResponse(channel, "BINGPS: OK");
             
             // Identification
-            long deviceId;
             QueryStringDecoder decoder = new QueryStringDecoder(request.getUri());
-            String imei = decoder.getParameters().get("imei").get(0);
-            try {
-                deviceId = getDataManager().getDeviceByImei(imei).getId();
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + imei);
+            if (!identify(decoder.getParameters().get("imei").get(0))) {
                 return null;
             }
 
@@ -108,7 +103,7 @@ public class PiligrimProtocolDecoder extends BaseProtocolDecoder {
                     
                     Position position = new Position();
                     ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
-                    position.setDeviceId(deviceId);
+                    position.setDeviceId(getDeviceId());
                     
                     // Time
                     Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
@@ -178,9 +173,7 @@ public class PiligrimProtocolDecoder extends BaseProtocolDecoder {
                 } else if (type == MSG_EVENTS) {
                     
                     buf.skipBytes(13);
-                    
                 }
-                
             }
             
             return positions;
diff --git a/src/org/traccar/protocol/ProgressProtocolDecoder.java b/src/org/traccar/protocol/ProgressProtocolDecoder.java
index 3f120445c..04584b884 100644
--- a/src/org/traccar/protocol/ProgressProtocolDecoder.java
+++ b/src/org/traccar/protocol/ProgressProtocolDecoder.java
@@ -34,22 +34,15 @@ import org.traccar.helper.Log;
 import org.traccar.model.ExtendedInfoFormatter;
 import org.traccar.model.Position;
 
-/**
- * Progress tracker protocol decoder
- */
 public class ProgressProtocolDecoder extends BaseProtocolDecoder {
 
-    private long deviceId;
     private long lastIndex;
     private long newIndex;
 
-    public ProgressProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public ProgressProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
-    /*
-     * Message types
-     */
     private static final int MSG_NULL = 0;
     private static final int MSG_IDENT = 1;
     private static final int MSG_IDENT_FULL = 2;
@@ -80,9 +73,6 @@ public class ProgressProtocolDecoder extends BaseProtocolDecoder {
         }*/
     }
 
-    /**
-     * Request archive messages
-     */
     private void requestArchive(Channel channel) {
         if (lastIndex == 0) {
             lastIndex = newIndex;
@@ -112,16 +102,13 @@ public class ProgressProtocolDecoder extends BaseProtocolDecoder {
             buf.skipBytes(length);
             length = buf.readUnsignedShort();
             String imei = buf.readBytes(length).toString(Charset.defaultCharset());
-            try {
-                deviceId = getDataManager().getDeviceByImei(imei).getId();
+            if (identify(imei)) {
                 loadLastIndex();
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + imei + " (id - " + id + ")");
             }
         }
 
         // Position
-        else if (deviceId != 0 && (type == MSG_POINT || type == MSG_ALARM || type == MSG_LOGMSG)) {
+        else if (hasDeviceId() && (type == MSG_POINT || type == MSG_ALARM || type == MSG_LOGMSG)) {
             List<Position> positions = new LinkedList<Position>();
 
             int recordCount = 1;
@@ -132,7 +119,7 @@ public class ProgressProtocolDecoder extends BaseProtocolDecoder {
             for (int j = 0; j < recordCount; j++) {
                 Position position = new Position();
                 ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
-                position.setDeviceId(deviceId);
+                position.setDeviceId(getDeviceId());
 
                 // Message index
                 if (type == MSG_LOGMSG) {
diff --git a/src/org/traccar/protocol/Pt3000ProtocolDecoder.java b/src/org/traccar/protocol/Pt3000ProtocolDecoder.java
index 86c438f6c..513fdbb4b 100644
--- a/src/org/traccar/protocol/Pt3000ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Pt3000ProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class Pt3000ProtocolDecoder extends BaseProtocolDecoder {
 
-    public Pt3000ProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public Pt3000ProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     static private Pattern pattern = Pattern.compile(
@@ -70,12 +70,10 @@ public class Pt3000ProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Identifier
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
-        }        
+        if (!identify(parser.group(index++))) {
+            return null;
+        }
+        position.setDeviceId(getDeviceId());
         
         // Time
         Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
@@ -85,7 +83,7 @@ public class Pt3000ProtocolDecoder extends BaseProtocolDecoder {
         time.set(Calendar.SECOND, Integer.valueOf(parser.group(index++)));
 
         // Validity
-        position.setValid(parser.group(index++).compareTo("A") == 0 ? true : false);
+        position.setValid(parser.group(index++).compareTo("A") == 0);
 
         // Latitude
         Double latitude = Double.valueOf(parser.group(index++));
diff --git a/src/org/traccar/protocol/Pt502ProtocolDecoder.java b/src/org/traccar/protocol/Pt502ProtocolDecoder.java
index 72f95a0f6..2cf5ad3d6 100644
--- a/src/org/traccar/protocol/Pt502ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Pt502ProtocolDecoder.java
@@ -33,8 +33,8 @@ import org.traccar.model.Position;
 

 public class Pt502ProtocolDecoder extends BaseProtocolDecoder {

 

-    public Pt502ProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {

-        super(dataManager, protocol, properties);

+    public Pt502ProtocolDecoder(String protocol) {

+        super(protocol);

     }

 

     private static final Pattern pattern = Pattern.compile(

@@ -71,13 +71,10 @@ public class Pt502ProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;

 

         // Get device by IMEI

-        String id = parser.group(index++);

-        try {

-            position.setDeviceId(getDataManager().getDeviceByImei(id).getId());

-        } catch(Exception error) {

-            Log.warning("Unknown device - " + id);

+        if (!identify(parser.group(index++))) {

             return null;

         }

+        position.setDeviceId(getDeviceId());

 

         // Time

         Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));

diff --git a/src/org/traccar/protocol/RitiProtocolDecoder.java b/src/org/traccar/protocol/RitiProtocolDecoder.java
index 4bc04501c..58e744f1a 100644
--- a/src/org/traccar/protocol/RitiProtocolDecoder.java
+++ b/src/org/traccar/protocol/RitiProtocolDecoder.java
@@ -35,8 +35,8 @@ import org.traccar.model.Position;
 
 public class RitiProtocolDecoder extends BaseProtocolDecoder {
 
-    public RitiProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public RitiProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -66,13 +66,11 @@ public class RitiProtocolDecoder extends BaseProtocolDecoder {
         buf.skipBytes(2); // header
 
         // Get device id
-        String id = String.valueOf(buf.readUnsignedShort());
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(id).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + id);
+        if (!identify(String.valueOf(buf.readUnsignedShort()))) {
+            return null;
         }
-        
+        position.setDeviceId(getDeviceId());
+
         extendedInfo.set("mode", buf.readUnsignedByte());
         extendedInfo.set("command", buf.readUnsignedByte());
         extendedInfo.set("power", buf.readUnsignedShort());
diff --git a/src/org/traccar/protocol/RuptelaProtocolDecoder.java b/src/org/traccar/protocol/RuptelaProtocolDecoder.java
index 0574aa2d8..b83d9f721 100644
--- a/src/org/traccar/protocol/RuptelaProtocolDecoder.java
+++ b/src/org/traccar/protocol/RuptelaProtocolDecoder.java
@@ -33,8 +33,8 @@ import org.traccar.model.Position;
 
 public class RuptelaProtocolDecoder extends BaseProtocolDecoder {
     
-    public RuptelaProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public RuptelaProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final int COMMAND_RECORDS = 0x01;
@@ -49,14 +49,10 @@ public class RuptelaProtocolDecoder extends BaseProtocolDecoder {
 
         // Identify device
         String imei = String.format("%015d", buf.readLong());
-        long deviceId;
-        try {
-            deviceId = getDataManager().getDeviceByImei(imei).getId();
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(imei)) {
             return null;
         }
-        
+
         int type = buf.readUnsignedByte();
         
         if (type == COMMAND_RECORDS) {
@@ -68,7 +64,7 @@ public class RuptelaProtocolDecoder extends BaseProtocolDecoder {
             for (int i = 0; i < count; i++) {
                 Position position = new Position();
                 ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
-                position.setDeviceId(deviceId);
+                position.setDeviceId(getDeviceId());
 
                 // Time
                 position.setTime(new Date(buf.readUnsignedInt() * 1000));
diff --git a/src/org/traccar/protocol/SanavProtocolDecoder.java b/src/org/traccar/protocol/SanavProtocolDecoder.java
index 343dc87c8..abdb25d2c 100644
--- a/src/org/traccar/protocol/SanavProtocolDecoder.java
+++ b/src/org/traccar/protocol/SanavProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class SanavProtocolDecoder extends BaseProtocolDecoder {
 
-    public SanavProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public SanavProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -69,13 +69,10 @@ public class SanavProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Identification
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Time
         Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
diff --git a/src/org/traccar/protocol/SkypatrolProtocolDecoder.java b/src/org/traccar/protocol/SkypatrolProtocolDecoder.java
index aa47e42fb..51150a8e9 100644
--- a/src/org/traccar/protocol/SkypatrolProtocolDecoder.java
+++ b/src/org/traccar/protocol/SkypatrolProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class SkypatrolProtocolDecoder extends BaseProtocolDecoder {
 
-    public SkypatrolProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public SkypatrolProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static boolean checkBit(long mask, int bit) {
@@ -98,12 +98,10 @@ public class SkypatrolProtocolDecoder extends BaseProtocolDecoder {
                 Log.warning("No device id field");
                 return null;
             }
-            try {
-                position.setDeviceId(getDataManager().getDeviceByImei(id).getId());
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + id);
+            if (!identify(id)) {
                 return null;
             }
+            position.setDeviceId(getDeviceId());
 
             // IO data
             if (checkBit(mask, 3)) {
diff --git a/src/org/traccar/protocol/Stl060ProtocolDecoder.java b/src/org/traccar/protocol/Stl060ProtocolDecoder.java
index 51af0941e..44cf20118 100644
--- a/src/org/traccar/protocol/Stl060ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Stl060ProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class Stl060ProtocolDecoder extends BaseProtocolDecoder {
 
-    public Stl060ProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public Stl060ProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -75,13 +75,10 @@ public class Stl060ProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Device identification
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
         
         // Date
         Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
diff --git a/src/org/traccar/protocol/SuntechProtocolDecoder.java b/src/org/traccar/protocol/SuntechProtocolDecoder.java
index cdfca7905..b2bbcf573 100644
--- a/src/org/traccar/protocol/SuntechProtocolDecoder.java
+++ b/src/org/traccar/protocol/SuntechProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class SuntechProtocolDecoder extends BaseProtocolDecoder {
 
-    public SuntechProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public SuntechProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     static private Pattern pattern = Pattern.compile(
@@ -70,13 +70,10 @@ public class SuntechProtocolDecoder extends BaseProtocolDecoder {
         int index = 1;
 
         // Identifier
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
         
         // Version
         extendedInfo.set("version", parser.group(index++));
diff --git a/src/org/traccar/protocol/SyrusProtocolDecoder.java b/src/org/traccar/protocol/SyrusProtocolDecoder.java
index ee11b35ef..5b7440bf9 100644
--- a/src/org/traccar/protocol/SyrusProtocolDecoder.java
+++ b/src/org/traccar/protocol/SyrusProtocolDecoder.java
@@ -35,9 +35,8 @@ public class SyrusProtocolDecoder extends BaseProtocolDecoder {
     
     boolean sendResponse;
 
-
-    public SyrusProtocolDecoder(DataManager dataManager, String protocol, Properties properties, boolean sendResponse) {
-        super(dataManager, protocol, properties);
+    public SyrusProtocolDecoder(String protocol, boolean sendResponse) {
+        super(protocol);
         this.sendResponse = sendResponse;
     }
 
@@ -102,7 +101,6 @@ public class SyrusProtocolDecoder extends BaseProtocolDecoder {
         }
 
         // Find device ID
-        Long deviceId = null;
         beginIndex = sentence.indexOf(";ID=");
         if (beginIndex != -1) {
             beginIndex += 4;
@@ -113,13 +111,10 @@ public class SyrusProtocolDecoder extends BaseProtocolDecoder {
 
             // Find device in database
             String id = sentence.substring(beginIndex, endIndex);
-            try {
-                deviceId = getDataManager().getDeviceByImei(id).getId();
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + id);
+            if (!identify(id)) {
                 return null;
             }
-            
+
             // Send response
             if (sendResponse && channel != null) {
                 channel.write(id);
@@ -137,7 +132,7 @@ public class SyrusProtocolDecoder extends BaseProtocolDecoder {
         // Create new position
         Position position = new Position();
         ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
-        position.setDeviceId(deviceId);
+        position.setDeviceId(getDeviceId());
 
         Integer index = 1;
         
diff --git a/src/org/traccar/protocol/T55ProtocolDecoder.java b/src/org/traccar/protocol/T55ProtocolDecoder.java
index 25b7f367f..ccf56ea41 100644
--- a/src/org/traccar/protocol/T55ProtocolDecoder.java
+++ b/src/org/traccar/protocol/T55ProtocolDecoder.java
@@ -32,10 +32,8 @@ import org.traccar.model.Position;
 
 public class T55ProtocolDecoder extends BaseProtocolDecoder {
 
-    private Long deviceId;
-
-    public T55ProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public T55ProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern patternGPRMC = Pattern.compile(
@@ -83,15 +81,7 @@ public class T55ProtocolDecoder extends BaseProtocolDecoder {
             "(-?\\d+\\.\\d+)," +           // Altitude
             "(\\d+\\.?\\d*)," +            // Battery
             ".+");
-    
-    private void identify(String id) {
-        try {
-            deviceId = getDataManager().getDeviceByImei(id).getId();
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + id);
-        }
-    }
-    
+
     @Override
     protected Object decode(
             ChannelHandlerContext ctx, Channel channel, Object msg)
@@ -135,7 +125,7 @@ public class T55ProtocolDecoder extends BaseProtocolDecoder {
         }
 
         // Location
-        else if (sentence.startsWith("$GPRMC") && deviceId != null) {
+        else if (sentence.startsWith("$GPRMC") && hasDeviceId()) {
 
             // Send response
             if (channel != null) {
@@ -151,7 +141,7 @@ public class T55ProtocolDecoder extends BaseProtocolDecoder {
             // Create new position
             Position position = new Position();
             ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
-            position.setDeviceId(deviceId);
+            position.setDeviceId(getDeviceId());
 
             Integer index = 1;
 
@@ -207,7 +197,7 @@ public class T55ProtocolDecoder extends BaseProtocolDecoder {
         }
 
         // Location
-        else if (sentence.startsWith("$GPGGA") && deviceId != null) {
+        else if (sentence.startsWith("$GPGGA") && hasDeviceId()) {
 
             // Parse message
             Matcher parser = patternGPGGA.matcher(sentence);
@@ -218,7 +208,7 @@ public class T55ProtocolDecoder extends BaseProtocolDecoder {
             // Create new position
             Position position = new Position();
             ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
-            position.setDeviceId(deviceId);
+            position.setDeviceId(getDeviceId());
 
             Integer index = 1;
 
@@ -259,7 +249,7 @@ public class T55ProtocolDecoder extends BaseProtocolDecoder {
         }
 
         // Location
-        else if (sentence.startsWith("$GPRMA") && deviceId != null) {
+        else if (sentence.startsWith("$GPRMA") && hasDeviceId()) {
 
             // Parse message
             Matcher parser = patternGPRMA.matcher(sentence);
@@ -270,7 +260,7 @@ public class T55ProtocolDecoder extends BaseProtocolDecoder {
             // Create new position
             Position position = new Position();
             ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
-            position.setDeviceId(deviceId);
+            position.setDeviceId(getDeviceId());
 
             Integer index = 1;
 
@@ -316,7 +306,7 @@ public class T55ProtocolDecoder extends BaseProtocolDecoder {
         }
 
         // Location
-        else if (sentence.startsWith("$TRCCR") && deviceId != null) {
+        else if (sentence.startsWith("$TRCCR") && hasDeviceId()) {
 
             // Parse message
             Matcher parser = patternTRCCR.matcher(sentence);
@@ -327,7 +317,7 @@ public class T55ProtocolDecoder extends BaseProtocolDecoder {
             // Create new position
             Position position = new Position();
             ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
-            position.setDeviceId(deviceId);
+            position.setDeviceId(getDeviceId());
 
             Integer index = 1;
 
diff --git a/src/org/traccar/protocol/TelikProtocolDecoder.java b/src/org/traccar/protocol/TelikProtocolDecoder.java
index 84dd6fb0b..15ad77e6b 100644
--- a/src/org/traccar/protocol/TelikProtocolDecoder.java
+++ b/src/org/traccar/protocol/TelikProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class TelikProtocolDecoder extends BaseProtocolDecoder {
 
-    public TelikProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public TelikProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -70,13 +70,10 @@ public class TelikProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Get device by IMEI
-        String id = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(id).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + id);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Message type
         extendedInfo.set("type", parser.group(index++));
diff --git a/src/org/traccar/protocol/TeltonikaProtocolDecoder.java b/src/org/traccar/protocol/TeltonikaProtocolDecoder.java
index 961d4e73b..f39a81fbc 100644
--- a/src/org/traccar/protocol/TeltonikaProtocolDecoder.java
+++ b/src/org/traccar/protocol/TeltonikaProtocolDecoder.java
@@ -36,8 +36,8 @@ public class TeltonikaProtocolDecoder extends BaseProtocolDecoder {
     
     private long deviceId;
 
-    public TeltonikaProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public TeltonikaProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private void parseIdentification(Channel channel, ChannelBuffer buf) {
@@ -45,13 +45,8 @@ public class TeltonikaProtocolDecoder extends BaseProtocolDecoder {
 
         int length = buf.readUnsignedShort();
         String imei = buf.toString(buf.readerIndex(), length, Charset.defaultCharset());
-        try {
-            deviceId = getDataManager().getDeviceByImei(imei).getId();
-            result = true;
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
-        }
-        
+        result = identify(imei);
+
         if (channel != null) {
             ChannelBuffer response = ChannelBuffers.directBuffer(1);
             response.writeByte(result ? 1 : 0);
diff --git a/src/org/traccar/protocol/Tk102ProtocolDecoder.java b/src/org/traccar/protocol/Tk102ProtocolDecoder.java
index bb9a5fbd2..b32b020d1 100644
--- a/src/org/traccar/protocol/Tk102ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Tk102ProtocolDecoder.java
@@ -32,10 +32,8 @@ import org.traccar.model.Position;
 
 public class Tk102ProtocolDecoder extends BaseProtocolDecoder {
 
-    private Long deviceId;
-
-    public Tk102ProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public Tk102ProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     static private Pattern pattern = Pattern.compile(
@@ -59,11 +57,7 @@ public class Tk102ProtocolDecoder extends BaseProtocolDecoder {
 
         // Login
         if (sentence.startsWith("[!")) {
-            String imei = sentence.substring(14, 14 + 15);
-            try {
-                deviceId = getDataManager().getDeviceByImei(imei).getId();
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + imei);
+            if (!identify(sentence.substring(14, 14 + 15))) {
                 return null;
             }
 
@@ -78,7 +72,7 @@ public class Tk102ProtocolDecoder extends BaseProtocolDecoder {
         }
 
         // Parse message
-        else if (deviceId != null) {
+        else if (hasDeviceId()) {
 
             // Parse message
             Matcher parser = pattern.matcher(sentence);
@@ -89,7 +83,7 @@ public class Tk102ProtocolDecoder extends BaseProtocolDecoder {
             // Create new position
             Position position = new Position();
             ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
-            position.setDeviceId(deviceId);
+            position.setDeviceId(getDeviceId());
 
             Integer index = 1;
 
@@ -101,7 +95,7 @@ public class Tk102ProtocolDecoder extends BaseProtocolDecoder {
             time.set(Calendar.SECOND, Integer.valueOf(parser.group(index++)));
 
             // Validity
-            position.setValid(parser.group(index++).compareTo("A") == 0 ? true : false);
+            position.setValid(parser.group(index++).compareTo("A") == 0);
 
             // Latitude
             Double latitude = Double.valueOf(parser.group(index++));
diff --git a/src/org/traccar/protocol/Tk103ProtocolDecoder.java b/src/org/traccar/protocol/Tk103ProtocolDecoder.java
index f8955b1df..fa589956a 100644
--- a/src/org/traccar/protocol/Tk103ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Tk103ProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class Tk103ProtocolDecoder extends BaseProtocolDecoder {
 
-    public Tk103ProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public Tk103ProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -89,18 +89,10 @@ public class Tk103ProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Get device by IMEI
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            // Compatibility mode (remove in future)
-            try {
-                position.setDeviceId(getDataManager().getDeviceByImei("000" + imei).getId());
-            } catch(Exception error2) {
-                Log.warning("Unknown device - " + imei);
-                return null;
-            }
+        if (!identify(parser.group(index++))) {
+            return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Date
         Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
diff --git a/src/org/traccar/protocol/Tlt2hProtocolDecoder.java b/src/org/traccar/protocol/Tlt2hProtocolDecoder.java
index 0e17fc70c..01c1ac2aa 100644
--- a/src/org/traccar/protocol/Tlt2hProtocolDecoder.java
+++ b/src/org/traccar/protocol/Tlt2hProtocolDecoder.java
@@ -34,8 +34,8 @@ import org.traccar.model.Position;
 
 public class Tlt2hProtocolDecoder extends BaseProtocolDecoder {
 
-    public Tlt2hProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public Tlt2hProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern patternHeader = Pattern.compile(
@@ -75,15 +75,10 @@ public class Tlt2hProtocolDecoder extends BaseProtocolDecoder {
         }
 
         // Get device identifier
-        String imei = parser.group(1);
-        long deviceId;
-        try {
-            deviceId = getDataManager().getDeviceByImei(imei).getId();
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(1))) {
             return null;
         }
-        
+
         // Get status
         String status = parser.group(2);
         
@@ -95,7 +90,7 @@ public class Tlt2hProtocolDecoder extends BaseProtocolDecoder {
             if (parser.matches()) {
                 Position position = new Position();
                 ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
-                position.setDeviceId(deviceId);
+                position.setDeviceId(getDeviceId());
 
                 Integer index = 1;
                 
diff --git a/src/org/traccar/protocol/TopflytechProtocolDecoder.java b/src/org/traccar/protocol/TopflytechProtocolDecoder.java
index 9e9a7e3e3..20c4e54ad 100644
--- a/src/org/traccar/protocol/TopflytechProtocolDecoder.java
+++ b/src/org/traccar/protocol/TopflytechProtocolDecoder.java
@@ -34,8 +34,8 @@ public class TopflytechProtocolDecoder extends BaseProtocolDecoder {
 
     private Long deviceId;
 
-    public TopflytechProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public TopflytechProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     static private Pattern pattern = Pattern.compile(
@@ -71,13 +71,10 @@ public class TopflytechProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Identifier
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Time
         Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
@@ -91,7 +88,7 @@ public class TopflytechProtocolDecoder extends BaseProtocolDecoder {
         position.setTime(time.getTime());
 
         // Validity
-        position.setValid(parser.group(index++).compareTo("A") == 0 ? true : false);
+        position.setValid(parser.group(index++).compareTo("A") == 0);
 
         // Latitude
         Double latitude = Double.valueOf(parser.group(index++));
diff --git a/src/org/traccar/protocol/TotemProtocolDecoder.java b/src/org/traccar/protocol/TotemProtocolDecoder.java
index 5c0cc9bec..ae8335b78 100644
--- a/src/org/traccar/protocol/TotemProtocolDecoder.java
+++ b/src/org/traccar/protocol/TotemProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class TotemProtocolDecoder extends BaseProtocolDecoder {
 
-    public TotemProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public TotemProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern patternFirst = Pattern.compile(
@@ -156,7 +156,7 @@ public class TotemProtocolDecoder extends BaseProtocolDecoder {
         } else if (format == MessageFormat.third) {
             parser = patternThird.matcher(sentence);
         }
-        if (parser == null || !parser.matches()) {
+        if (!parser.matches()) {
             return null;
         }
 
@@ -167,13 +167,10 @@ public class TotemProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Get device by IMEI
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
         
         // Alarm type
         extendedInfo.set("alarm", parser.group(index++));
diff --git a/src/org/traccar/protocol/Tr20ProtocolDecoder.java b/src/org/traccar/protocol/Tr20ProtocolDecoder.java
index fb6f319d5..9bd1ccaaf 100644
--- a/src/org/traccar/protocol/Tr20ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Tr20ProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class Tr20ProtocolDecoder extends BaseProtocolDecoder {
 
-    public Tr20ProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public Tr20ProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     static private Pattern patternPing = Pattern.compile(
@@ -85,16 +85,13 @@ public class Tr20ProtocolDecoder extends BaseProtocolDecoder {
             Integer index = 1;
 
             // Get device by id
-            String id = parser.group(index++);
-            try {
-                position.setDeviceId(getDataManager().getDeviceByImei(id).getId());
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + id);
+            if (!identify(parser.group(index++))) {
                 return null;
             }
+            position.setDeviceId(getDeviceId());
 
             // Validity
-            position.setValid(parser.group(index++).compareTo("A") == 0 ? true : false);
+            position.setValid(parser.group(index++).compareTo("A") == 0);
 
             // Time
             Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
diff --git a/src/org/traccar/protocol/Tr900ProtocolDecoder.java b/src/org/traccar/protocol/Tr900ProtocolDecoder.java
index da307efc9..f8890f954 100644
--- a/src/org/traccar/protocol/Tr900ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Tr900ProtocolDecoder.java
@@ -31,8 +31,8 @@ import java.util.regex.Pattern;
 
 public class Tr900ProtocolDecoder extends BaseProtocolDecoder {
 
-    public Tr900ProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public Tr900ProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -76,13 +76,10 @@ public class Tr900ProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Identification
-        String id = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(id).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + id);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Validity
         position.setValid(parser.group(index++).compareTo("1") == 0);
diff --git a/src/org/traccar/protocol/TrackboxProtocolDecoder.java b/src/org/traccar/protocol/TrackboxProtocolDecoder.java
index 186bc24cd..5be74b15d 100644
--- a/src/org/traccar/protocol/TrackboxProtocolDecoder.java
+++ b/src/org/traccar/protocol/TrackboxProtocolDecoder.java
@@ -32,10 +32,8 @@ import org.traccar.model.Position;
 
 public class TrackboxProtocolDecoder extends BaseProtocolDecoder {
     
-    private Long deviceId;
-
-    public TrackboxProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public TrackboxProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -66,11 +64,8 @@ public class TrackboxProtocolDecoder extends BaseProtocolDecoder {
 
         if (sentence.startsWith("a=connect")) {
             String id = sentence.substring(sentence.indexOf("i=") + 2);
-            try {
-                deviceId = getDataManager().getDeviceByImei(id).getId();
+            if (identify(id)) {
                 sendResponse(channel);
-            } catch(Exception error) {
-              Log.warning("Unknown device - " + id);
             }
         }
         
@@ -84,7 +79,7 @@ public class TrackboxProtocolDecoder extends BaseProtocolDecoder {
 
             // Create new position
             Position position = new Position();
-            position.setDeviceId(deviceId);
+            position.setDeviceId(getDeviceId());
             ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
 
             Integer index = 1;
diff --git a/src/org/traccar/protocol/TramigoProtocolDecoder.java b/src/org/traccar/protocol/TramigoProtocolDecoder.java
index a31f3294b..e0bab0483 100644
--- a/src/org/traccar/protocol/TramigoProtocolDecoder.java
+++ b/src/org/traccar/protocol/TramigoProtocolDecoder.java
@@ -37,8 +37,8 @@ import java.util.regex.Pattern;
 
 public class TramigoProtocolDecoder extends BaseProtocolDecoder {
 
-    public TramigoProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public TramigoProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final int MSG_COMPACT = 0x0100;
@@ -68,12 +68,10 @@ public class TramigoProtocolDecoder extends BaseProtocolDecoder {
         position.setValid(true);
 
         // Get device id
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(String.valueOf(id)).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + id);
+        if (!identify(String.valueOf(id))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         if (protocol == 0x01 && (type == MSG_COMPACT || type == MSG_FULL)) {
 
@@ -147,7 +145,6 @@ public class TramigoProtocolDecoder extends BaseProtocolDecoder {
 
             position.setExtendedInfo(extendedInfo.toString());
             return position;
-
         }
 
         return null;
diff --git a/src/org/traccar/protocol/TytanProtocolDecoder.java b/src/org/traccar/protocol/TytanProtocolDecoder.java
index 5b3772d31..e0dc7f68e 100644
--- a/src/org/traccar/protocol/TytanProtocolDecoder.java
+++ b/src/org/traccar/protocol/TytanProtocolDecoder.java
@@ -34,13 +34,10 @@ import org.traccar.model.Position;
 
 public class TytanProtocolDecoder extends BaseProtocolDecoder {
 
-    public TytanProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public TytanProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
-    private static final int MSG_HEARTBEAT = 0x1A;
-    private static final int MSG_DATA = 0x10;
-
     @Override
     protected Object decode(
             ChannelHandlerContext ctx, Channel channel, SocketAddress remoteAddress, Object msg)
@@ -58,21 +55,17 @@ public class TytanProtocolDecoder extends BaseProtocolDecoder {
         }
         
         String id = String.valueOf(buf.readUnsignedInt());
-        long deviceId;
-        try {
-            deviceId = getDataManager().getDeviceByImei(id).getId();
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + id);
+        if (!identify(id)) {
             return null;
         }
-        
+
         List<Position> positions = new LinkedList<Position>();
         
         while (buf.readable()) {
             
             Position position = new Position();
             ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
-            position.setDeviceId(deviceId);
+            position.setDeviceId(getDeviceId());
             
             int end = buf.readerIndex() + buf.readUnsignedByte();
             
diff --git a/src/org/traccar/protocol/UlbotechProtocolDecoder.java b/src/org/traccar/protocol/UlbotechProtocolDecoder.java
index c5f63812e..48122a8f3 100644
--- a/src/org/traccar/protocol/UlbotechProtocolDecoder.java
+++ b/src/org/traccar/protocol/UlbotechProtocolDecoder.java
@@ -30,8 +30,8 @@ import java.util.Properties;
 
 public class UlbotechProtocolDecoder extends BaseProtocolDecoder {
 
-    public UlbotechProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public UlbotechProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final short DATA_GPS = 0x01;
@@ -63,11 +63,10 @@ public class UlbotechProtocolDecoder extends BaseProtocolDecoder {
 
         // Get device id
         String imei = ChannelBufferTools.readHexString(buf, 16).substring(1);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(imei)) {
+            return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Time
         long seconds = buf.readUnsignedInt() & 0x7fffffffl;
@@ -82,7 +81,6 @@ public class UlbotechProtocolDecoder extends BaseProtocolDecoder {
             switch (type) {
 
                 case DATA_GPS:
-
                     position.setValid(true);
                     position.setLatitude(buf.readInt() / 1000000.0);
                     position.setLongitude(buf.readInt() / 1000000.0);
@@ -90,10 +88,8 @@ public class UlbotechProtocolDecoder extends BaseProtocolDecoder {
                     position.setSpeed(buf.readUnsignedShort() * 0.539957);
                     position.setCourse((double) buf.readUnsignedShort());
                     extendedInfo.set("hdop", buf.readUnsignedShort());
-
                     break;
 
-
                 default:
                     buf.skipBytes(length);
                     break;
diff --git a/src/org/traccar/protocol/V680ProtocolDecoder.java b/src/org/traccar/protocol/V680ProtocolDecoder.java
index 95f4e101c..6e85640c0 100644
--- a/src/org/traccar/protocol/V680ProtocolDecoder.java
+++ b/src/org/traccar/protocol/V680ProtocolDecoder.java
@@ -32,10 +32,8 @@ import org.traccar.model.Position;
 
 public class V680ProtocolDecoder extends BaseProtocolDecoder {
 
-    private Long deviceId;
-
-    public V680ProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public V680ProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -68,11 +66,7 @@ public class V680ProtocolDecoder extends BaseProtocolDecoder {
         // Detect device ID
         if (sentence.length() == 16) {
             String imei = sentence.substring(1, sentence.length());
-            try {
-                deviceId = getDataManager().getDeviceByImei(imei).getId();
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + imei);
-            }
+            identify(imei);
         } else {
 
             // Parse message
@@ -89,17 +83,12 @@ public class V680ProtocolDecoder extends BaseProtocolDecoder {
             // Get device by IMEI
             String imei = parser.group(index++);
             if (imei != null) {
-                try {
-                    deviceId = getDataManager().getDeviceByImei(imei).getId();
-                } catch(Exception error) {
-                    Log.warning("Unknown device - " + imei);
-                    return null;
-                }
+                identify(imei);
             }
-            if (deviceId == null) {
+            if (!hasDeviceId()) {
                 return null;
             }
-            position.setDeviceId(deviceId);
+            position.setDeviceId(getDeviceId());
 
             // User
             extendedInfo.set("user", parser.group(index++));
diff --git a/src/org/traccar/protocol/VisiontekProtocolDecoder.java b/src/org/traccar/protocol/VisiontekProtocolDecoder.java
index 242ac1083..b61500bd9 100644
--- a/src/org/traccar/protocol/VisiontekProtocolDecoder.java
+++ b/src/org/traccar/protocol/VisiontekProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class VisiontekProtocolDecoder extends BaseProtocolDecoder {
 
-    public VisiontekProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public VisiontekProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -81,22 +81,11 @@ public class VisiontekProtocolDecoder extends BaseProtocolDecoder {
         // Device identification
         String id = parser.group(index++);
         String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(id).getId());
-        } catch(Exception error) {
-            if (imei != null) {
-                try {
-                    position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-                } catch(Exception error2) {
-                    Log.warning("Unknown device - " + id);
-                    return null;
-                }
-            } else {
-                Log.warning("Unknown device - " + id);
-                return null;
-            }
+        if (!identify(id, false) && !identify(imei)) {
+            return null;
         }
-        
+        position.setDeviceId(getDeviceId());
+
         // Date
         Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
         time.clear();
diff --git a/src/org/traccar/protocol/WialonProtocolDecoder.java b/src/org/traccar/protocol/WialonProtocolDecoder.java
index 6c4c0e8db..76cf9b924 100644
--- a/src/org/traccar/protocol/WialonProtocolDecoder.java
+++ b/src/org/traccar/protocol/WialonProtocolDecoder.java
@@ -34,10 +34,8 @@ import org.traccar.model.Position;
 
 public class WialonProtocolDecoder extends BaseProtocolDecoder {
 
-    private Long deviceId;
-
-    public WialonProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public WialonProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -75,14 +73,14 @@ public class WialonProtocolDecoder extends BaseProtocolDecoder {
         
         // Parse message
         Matcher parser = pattern.matcher(substring);
-        if (deviceId == null || !parser.matches()) {
+        if (!hasDeviceId() || !parser.matches()) {
             return null;
         }
 
         // Create new position
         Position position = new Position();
         ExtendedInfoFormatter extendedInfo = new ExtendedInfoFormatter(getProtocol());
-        position.setDeviceId(deviceId);
+        position.setDeviceId(getDeviceId());
 
         Integer index = 1;
 
@@ -187,11 +185,8 @@ public class WialonProtocolDecoder extends BaseProtocolDecoder {
         // Detect device ID
         if (sentence.startsWith("#L#")) {
             String imei = sentence.substring(3, sentence.indexOf(';'));
-            try {
-                deviceId = getDataManager().getDeviceByImei(imei).getId();
+            if (identify(imei)) {
                 sendResponse(channel, "#AL#", 1);
-            } catch(Exception error) {
-                Log.warning("Unknown device - " + imei);
             }
         }
 
diff --git a/src/org/traccar/protocol/WondexProtocolDecoder.java b/src/org/traccar/protocol/WondexProtocolDecoder.java
index a9068e7be..98b75b0d2 100644
--- a/src/org/traccar/protocol/WondexProtocolDecoder.java
+++ b/src/org/traccar/protocol/WondexProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class WondexProtocolDecoder extends BaseProtocolDecoder {
 
-    public WondexProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public WondexProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -72,13 +72,10 @@ public class WondexProtocolDecoder extends BaseProtocolDecoder {
         int index = 1;
 
         // Device identifier
-        String id = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(id).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + id);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Time
         Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
diff --git a/src/org/traccar/protocol/Xexun2ProtocolDecoder.java b/src/org/traccar/protocol/Xexun2ProtocolDecoder.java
index d60e48750..bfd20c64b 100644
--- a/src/org/traccar/protocol/Xexun2ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Xexun2ProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class Xexun2ProtocolDecoder extends BaseProtocolDecoder {
 
-    public Xexun2ProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public Xexun2ProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     static private Pattern pattern = Pattern.compile(
@@ -94,7 +94,7 @@ public class Xexun2ProtocolDecoder extends BaseProtocolDecoder {
         time.set(Calendar.MILLISECOND, Integer.valueOf(parser.group(index++)));
 
         // Validity
-        position.setValid(parser.group(index++).compareTo("A") == 0 ? true : false);
+        position.setValid(parser.group(index++).compareTo("A") == 0);
 
         // Latitude
         Double latitude = Double.valueOf(parser.group(index++));
@@ -132,13 +132,10 @@ public class Xexun2ProtocolDecoder extends BaseProtocolDecoder {
         extendedInfo.set("alarm", parser.group(index++));
 
         // Get device by IMEI
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Satellites
         extendedInfo.set("satellites", parser.group(index++).replaceFirst ("^0*(?![\\.$])", ""));
diff --git a/src/org/traccar/protocol/XexunProtocolDecoder.java b/src/org/traccar/protocol/XexunProtocolDecoder.java
index dd9ed0528..bf119808d 100644
--- a/src/org/traccar/protocol/XexunProtocolDecoder.java
+++ b/src/org/traccar/protocol/XexunProtocolDecoder.java
@@ -33,8 +33,8 @@ import org.traccar.model.Position;
 
 public class XexunProtocolDecoder extends BaseProtocolDecoder {
 
-    public XexunProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public XexunProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -116,13 +116,10 @@ public class XexunProtocolDecoder extends BaseProtocolDecoder {
         position.setTime(time.getTime());
 
         // Get device by IMEI
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         position.setExtendedInfo(extendedInfo.toString());
         return position;
diff --git a/src/org/traccar/protocol/XirgoProtocolDecoder.java b/src/org/traccar/protocol/XirgoProtocolDecoder.java
index e6a7bd10b..cec36c866 100644
--- a/src/org/traccar/protocol/XirgoProtocolDecoder.java
+++ b/src/org/traccar/protocol/XirgoProtocolDecoder.java
@@ -33,8 +33,8 @@ import org.traccar.model.Position;
 
 public class XirgoProtocolDecoder extends BaseProtocolDecoder {
 
-    public XirgoProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public XirgoProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -76,13 +76,10 @@ public class XirgoProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Get device by IMEI
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         extendedInfo.set("event", parser.group(index++));
         
diff --git a/src/org/traccar/protocol/Xt013ProtocolDecoder.java b/src/org/traccar/protocol/Xt013ProtocolDecoder.java
index 389ed3b59..e471ea349 100644
--- a/src/org/traccar/protocol/Xt013ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Xt013ProtocolDecoder.java
@@ -32,8 +32,8 @@ import java.util.regex.Pattern;
 
 public class Xt013ProtocolDecoder extends BaseProtocolDecoder {
 
-    public Xt013ProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public Xt013ProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -78,13 +78,10 @@ public class Xt013ProtocolDecoder extends BaseProtocolDecoder {
         Integer index = 1;
 
         // Identify device
-        String imei = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(imei).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + imei);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
 
         // Time
         Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
diff --git a/src/org/traccar/protocol/Xt7ProtocolDecoder.java b/src/org/traccar/protocol/Xt7ProtocolDecoder.java
index bd46cee37..1e5396f22 100644
--- a/src/org/traccar/protocol/Xt7ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Xt7ProtocolDecoder.java
@@ -34,8 +34,8 @@ import org.traccar.model.Position;
 
 public class Xt7ProtocolDecoder extends BaseProtocolDecoder {
 
-    public Xt7ProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public Xt7ProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -74,13 +74,11 @@ public class Xt7ProtocolDecoder extends BaseProtocolDecoder {
         
         // Get device by id
         String id = buf.readBytes(16).toString(Charset.defaultCharset()).trim();
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(id).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + id);
+        if (!identify(id)) {
             return null;
         }
-        
+        position.setDeviceId(getDeviceId());
+
         buf.readUnsignedByte(); // command
         int length = buf.readUnsignedByte();
         
diff --git a/src/org/traccar/protocol/YwtProtocolDecoder.java b/src/org/traccar/protocol/YwtProtocolDecoder.java
index 5392a4ccf..fa17d6f43 100644
--- a/src/org/traccar/protocol/YwtProtocolDecoder.java
+++ b/src/org/traccar/protocol/YwtProtocolDecoder.java
@@ -32,8 +32,8 @@ import org.traccar.model.Position;
 
 public class YwtProtocolDecoder extends BaseProtocolDecoder {
 
-    public YwtProtocolDecoder(DataManager dataManager, String protocol, Properties properties) {
-        super(dataManager, protocol, properties);
+    public YwtProtocolDecoder(String protocol) {
+        super(protocol);
     }
 
     private static final Pattern pattern = Pattern.compile(
@@ -89,13 +89,10 @@ public class YwtProtocolDecoder extends BaseProtocolDecoder {
         String type = parser.group(index++);
 
         // Device
-        String id = parser.group(index++);
-        try {
-            position.setDeviceId(getDataManager().getDeviceByImei(id).getId());
-        } catch(Exception error) {
-            Log.warning("Unknown device - " + id);
+        if (!identify(parser.group(index++))) {
             return null;
         }
+        position.setDeviceId(getDeviceId());
         
         // Time
         Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));