Migrate G protocols

44 files changed, 313 insertions, 326 deletions

diff --git a/src/org/traccar/BaseProtocol.java b/src/org/traccar/BaseProtocol.java
index 2cc24d3d9..1729edd54 100644
--- a/src/org/traccar/BaseProtocol.java
+++ b/src/org/traccar/BaseProtocol.java
@@ -16,7 +16,6 @@
 package org.traccar;
 
 import io.netty.buffer.Unpooled;
-import io.netty.handler.codec.string.StringEncoder;
 import org.traccar.database.ActiveDevice;
 import org.traccar.helper.DataConverter;
 import org.traccar.model.Command;
diff --git a/src/org/traccar/BaseProtocolDecoder.java b/src/org/traccar/BaseProtocolDecoder.java
index 31bf47e3f..fe41bd857 100644
--- a/src/org/traccar/BaseProtocolDecoder.java
+++ b/src/org/traccar/BaseProtocolDecoder.java
@@ -17,7 +17,6 @@ package org.traccar;
 
 import io.netty.channel.Channel;
 import io.netty.channel.socket.DatagramChannel;
-import io.netty.handler.codec.http.HttpRequestDecoder;
 import org.traccar.helper.Log;
 import org.traccar.helper.UnitsConverter;
 import org.traccar.model.Device;
diff --git a/src/org/traccar/EventLoopGroupFactory.java b/src/org/traccar/EventLoopGroupFactory.java
index 806a3a1dc..482559253 100644
--- a/src/org/traccar/EventLoopGroupFactory.java
+++ b/src/org/traccar/EventLoopGroupFactory.java
@@ -23,6 +23,9 @@ public final class EventLoopGroupFactory {
     private static EventLoopGroup bossGroup = new NioEventLoopGroup();
     private static EventLoopGroup workerGroup = new NioEventLoopGroup();
 
+    private EventLoopGroupFactory() {
+    }
+
     public static EventLoopGroup getBossGroup() {
         return bossGroup;
     }
diff --git a/src/org/traccar/WrapperOutboundHandler.java b/src/org/traccar/WrapperOutboundHandler.java
index ad342fa6c..b14cdb75a 100644
--- a/src/org/traccar/WrapperOutboundHandler.java
+++ b/src/org/traccar/WrapperOutboundHandler.java
@@ -35,7 +35,9 @@ public class WrapperOutboundHandler implements ChannelOutboundHandler {
     }
 
     @Override
-    public void connect(ChannelHandlerContext ctx, SocketAddress remoteAddress, SocketAddress localAddress, ChannelPromise promise) throws Exception {
+    public void connect(
+            ChannelHandlerContext ctx, SocketAddress remoteAddress,
+            SocketAddress localAddress, ChannelPromise promise) throws Exception {
         handler.connect(ctx, remoteAddress, localAddress, promise);
     }
 
diff --git a/src/org/traccar/helper/BufferUtil.java b/src/org/traccar/helper/BufferUtil.java
index b2768dbfd..c046fcaf5 100644
--- a/src/org/traccar/helper/BufferUtil.java
+++ b/src/org/traccar/helper/BufferUtil.java
@@ -22,7 +22,10 @@ import io.netty.buffer.ByteBuf;
 import io.netty.buffer.ByteBufUtil;
 import io.netty.buffer.Unpooled;
 
-public class BufferUtil {
+public final class BufferUtil {
+
+    private BufferUtil() {
+    }
 
     public static int indexOf(String needle, ByteBuf haystack) {
         return ByteBufUtil.indexOf(
diff --git a/src/org/traccar/protocol/GalileoFrameDecoder.java b/src/org/traccar/protocol/GalileoFrameDecoder.java
index 6d02ce744..5a57c3a95 100644
--- a/src/org/traccar/protocol/GalileoFrameDecoder.java
+++ b/src/org/traccar/protocol/GalileoFrameDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2013 Anton Tananaev (anton@traccar.org)
+ * Copyright 2013 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,28 +15,24 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.buffer.ChannelBuffer;
-import org.jboss.netty.channel.Channel;
-import org.jboss.netty.channel.ChannelHandlerContext;
-import org.jboss.netty.handler.codec.frame.FrameDecoder;
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelHandlerContext;
+import org.traccar.BaseFrameDecoder;
 
-public class GalileoFrameDecoder extends FrameDecoder {
+public class GalileoFrameDecoder extends BaseFrameDecoder {
 
     private static final int MESSAGE_MINIMUM_LENGTH = 5;
 
     @Override
     protected Object decode(
-            ChannelHandlerContext ctx,
-            Channel channel,
-            ChannelBuffer buf) throws Exception {
+            ChannelHandlerContext ctx, Channel channel, ByteBuf buf) throws Exception {
 
-        // Check minimum length
         if (buf.readableBytes() < MESSAGE_MINIMUM_LENGTH) {
             return null;
         }
 
-        // Read packet
-        int length = buf.getUnsignedShort(buf.readerIndex() + 1) & 0x7fff;
+        int length = buf.getUnsignedShortLE(buf.readerIndex() + 1) & 0x7fff;
         if (buf.readableBytes() >= (length + MESSAGE_MINIMUM_LENGTH)) {
             return buf.readBytes(length + MESSAGE_MINIMUM_LENGTH);
         }
diff --git a/src/org/traccar/protocol/GalileoProtocol.java b/src/org/traccar/protocol/GalileoProtocol.java
index f76de04a0..93178ea52 100644
--- a/src/org/traccar/protocol/GalileoProtocol.java
+++ b/src/org/traccar/protocol/GalileoProtocol.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 - 2017 Anton Tananaev (anton@traccar.org)
+ * Copyright 2015 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,13 +15,11 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.bootstrap.ServerBootstrap;
-import org.jboss.netty.channel.ChannelPipeline;
 import org.traccar.BaseProtocol;
+import org.traccar.PipelineBuilder;
 import org.traccar.TrackerServer;
 import org.traccar.model.Command;
 
-import java.nio.ByteOrder;
 import java.util.List;
 
 public class GalileoProtocol extends BaseProtocol {
@@ -35,16 +33,14 @@ public class GalileoProtocol extends BaseProtocol {
 
     @Override
     public void initTrackerServers(List<TrackerServer> serverList) {
-        TrackerServer server = new TrackerServer(new ServerBootstrap(), getName()) {
+        serverList.add(new TrackerServer(false, getName()) {
             @Override
-            protected void addSpecificHandlers(ChannelPipeline pipeline) {
+            protected void addProtocolHandlers(PipelineBuilder pipeline) {
                 pipeline.addLast("frameDecoder", new GalileoFrameDecoder());
                 pipeline.addLast("objectEncoder", new GalileoProtocolEncoder());
                 pipeline.addLast("objectDecoder", new GalileoProtocolDecoder(GalileoProtocol.this));
             }
-        };
-        server.setEndianness(ByteOrder.LITTLE_ENDIAN);
-        serverList.add(server);
+        });
     }
 
 }
diff --git a/src/org/traccar/protocol/GalileoProtocolDecoder.java b/src/org/traccar/protocol/GalileoProtocolDecoder.java
index d8a1651bb..9beb93e4c 100644
--- a/src/org/traccar/protocol/GalileoProtocolDecoder.java
+++ b/src/org/traccar/protocol/GalileoProtocolDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2013 - 2017 Anton Tananaev (anton@traccar.org)
+ * Copyright 2013 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,16 +15,17 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.buffer.ChannelBuffer;
-import org.jboss.netty.buffer.ChannelBuffers;
-import org.jboss.netty.channel.Channel;
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.ByteBufUtil;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.Channel;
 import org.traccar.BaseProtocolDecoder;
 import org.traccar.DeviceSession;
+import org.traccar.NetworkMessage;
 import org.traccar.helper.UnitsConverter;
 import org.traccar.model.Position;
 
 import java.net.SocketAddress;
-import java.nio.ByteOrder;
 import java.nio.charset.StandardCharsets;
 import java.util.Date;
 import java.util.HashMap;
@@ -92,15 +93,15 @@ public class GalileoProtocolDecoder extends BaseProtocolDecoder {
     }
 
     private void sendReply(Channel channel, int checksum) {
-        ChannelBuffer reply = ChannelBuffers.directBuffer(ByteOrder.LITTLE_ENDIAN, 3);
+        ByteBuf reply = Unpooled.buffer(3);
         reply.writeByte(0x02);
-        reply.writeShort((short) checksum);
+        reply.writeShortLE((short) checksum);
         if (channel != null) {
-            channel.write(reply);
+            channel.write(new NetworkMessage(reply, channel.remoteAddress()));
         }
     }
 
-    private void decodeTag(Position position, ChannelBuffer buf, int tag) {
+    private void decodeTag(Position position, ByteBuf buf, int tag) {
         switch (tag) {
             case 0x01:
                 position.set(Position.KEY_VERSION_HW, buf.readUnsignedByte());
@@ -109,41 +110,41 @@ public class GalileoProtocolDecoder extends BaseProtocolDecoder {
                 position.set(Position.KEY_VERSION_FW, buf.readUnsignedByte());
                 break;
             case 0x04:
-                position.set("deviceId", buf.readUnsignedShort());
+                position.set("deviceId", buf.readUnsignedShortLE());
                 break;
             case 0x10:
-                position.set(Position.KEY_INDEX, buf.readUnsignedShort());
+                position.set(Position.KEY_INDEX, buf.readUnsignedShortLE());
                 break;
             case 0x20:
-                position.setTime(new Date(buf.readUnsignedInt() * 1000));
+                position.setTime(new Date(buf.readUnsignedIntLE() * 1000));
                 break;
             case 0x33:
-                position.setSpeed(UnitsConverter.knotsFromKph(buf.readUnsignedShort() * 0.1));
-                position.setCourse(buf.readUnsignedShort() * 0.1);
+                position.setSpeed(UnitsConverter.knotsFromKph(buf.readUnsignedShortLE() * 0.1));
+                position.setCourse(buf.readUnsignedShortLE() * 0.1);
                 break;
             case 0x34:
-                position.setAltitude(buf.readShort());
+                position.setAltitude(buf.readShortLE());
                 break;
             case 0x40:
-                position.set(Position.KEY_STATUS, buf.readUnsignedShort());
+                position.set(Position.KEY_STATUS, buf.readUnsignedShortLE());
                 break;
             case 0x41:
-                position.set(Position.KEY_POWER, buf.readUnsignedShort());
+                position.set(Position.KEY_POWER, buf.readUnsignedShortLE());
                 break;
             case 0x42:
-                position.set(Position.KEY_BATTERY, buf.readUnsignedShort());
+                position.set(Position.KEY_BATTERY, buf.readUnsignedShortLE());
                 break;
             case 0x43:
                 position.set(Position.KEY_DEVICE_TEMP, buf.readByte());
                 break;
             case 0x44:
-                position.set(Position.KEY_ACCELERATION, buf.readUnsignedInt());
+                position.set(Position.KEY_ACCELERATION, buf.readUnsignedIntLE());
                 break;
             case 0x45:
-                position.set(Position.KEY_OUTPUT, buf.readUnsignedShort());
+                position.set(Position.KEY_OUTPUT, buf.readUnsignedShortLE());
                 break;
             case 0x46:
-                position.set(Position.KEY_INPUT, buf.readUnsignedShort());
+                position.set(Position.KEY_INPUT, buf.readUnsignedShortLE());
                 break;
             case 0x50:
             case 0x51:
@@ -153,27 +154,27 @@ public class GalileoProtocolDecoder extends BaseProtocolDecoder {
             case 0x55:
             case 0x56:
             case 0x57:
-                position.set(Position.PREFIX_ADC + (tag - 0x50), buf.readUnsignedShort());
+                position.set(Position.PREFIX_ADC + (tag - 0x50), buf.readUnsignedShortLE());
                 break;
             case 0x58:
-                position.set("rs2320", buf.readUnsignedShort());
+                position.set("rs2320", buf.readUnsignedShortLE());
                 break;
             case 0x59:
-                position.set("rs2321", buf.readUnsignedShort());
+                position.set("rs2321", buf.readUnsignedShortLE());
                 break;
             case 0xc0:
-                position.set("fuelTotal", buf.readUnsignedInt() * 0.5);
+                position.set("fuelTotal", buf.readUnsignedIntLE() * 0.5);
                 break;
             case 0xc1:
                 position.set(Position.KEY_FUEL_LEVEL, buf.readUnsignedByte() * 0.4);
                 position.set(Position.PREFIX_TEMP + 1, buf.readUnsignedByte() - 40);
-                position.set(Position.KEY_RPM, buf.readUnsignedShort() * 0.125);
+                position.set(Position.KEY_RPM, buf.readUnsignedShortLE() * 0.125);
                 break;
             case 0xc2:
-                position.set("canB0", buf.readUnsignedInt());
+                position.set("canB0", buf.readUnsignedIntLE());
                 break;
             case 0xc3:
-                position.set("canB1", buf.readUnsignedInt());
+                position.set("canB1", buf.readUnsignedIntLE());
                 break;
             case 0xc4:
             case 0xc5:
@@ -197,20 +198,20 @@ public class GalileoProtocolDecoder extends BaseProtocolDecoder {
             case 0xd8:
             case 0xd9:
             case 0xda:
-                position.set("can16Bit" + (tag - 0xd6), buf.readUnsignedShort());
+                position.set("can16Bit" + (tag - 0xd6), buf.readUnsignedShortLE());
                 break;
             case 0xdb:
             case 0xdc:
             case 0xdd:
             case 0xde:
             case 0xdf:
-                position.set("can32Bit" + (tag - 0xdb), buf.readUnsignedInt());
+                position.set("can32Bit" + (tag - 0xdb), buf.readUnsignedIntLE());
                 break;
             case 0xd4:
-                position.set(Position.KEY_ODOMETER, buf.readUnsignedInt());
+                position.set(Position.KEY_ODOMETER, buf.readUnsignedIntLE());
                 break;
             case 0xe0:
-                position.set(Position.KEY_INDEX, buf.readUnsignedInt());
+                position.set(Position.KEY_INDEX, buf.readUnsignedIntLE());
                 break;
             case 0xe1:
                 position.set(Position.KEY_RESULT,
@@ -224,10 +225,11 @@ public class GalileoProtocolDecoder extends BaseProtocolDecoder {
             case 0xe7:
             case 0xe8:
             case 0xe9:
-                position.set("userData" + (tag - 0xe2), buf.readUnsignedInt());
+                position.set("userData" + (tag - 0xe2), buf.readUnsignedIntLE());
                 break;
             case 0xea:
-                position.set("userDataArray", ChannelBuffers.hexDump(buf.readBytes(buf.readUnsignedByte())));
+                position.set("userDataArray", ByteBufUtil.hexDump(buf.readBytes(buf.readUnsignedByte())));
+                position.set("userDataArray", ByteBufUtil.hexDump(buf.readBytes(buf.readUnsignedByte())));
                 break;
             default:
                 buf.skipBytes(getTagLength(tag));
@@ -239,10 +241,10 @@ public class GalileoProtocolDecoder extends BaseProtocolDecoder {
     protected Object decode(
             Channel channel, SocketAddress remoteAddress, Object msg) throws Exception {
 
-        ChannelBuffer buf = (ChannelBuffer) msg;
+        ByteBuf buf = (ByteBuf) msg;
 
         buf.readUnsignedByte(); // header
-        int length = (buf.readUnsignedShort() & 0x7fff) + 3;
+        int length = (buf.readUnsignedShortLE() & 0x7fff) + 3;
 
         List<Position> positions = new LinkedList<>();
         Set<Integer> tags = new HashSet<>();
@@ -270,8 +272,8 @@ public class GalileoProtocolDecoder extends BaseProtocolDecoder {
             } else if (tag == 0x30) {
                 hasLocation = true;
                 position.setValid((buf.readUnsignedByte() & 0xf0) == 0x00);
-                position.setLatitude(buf.readInt() / 1000000.0);
-                position.setLongitude(buf.readInt() / 1000000.0);
+                position.setLatitude(buf.readIntLE() / 1000000.0);
+                position.setLongitude(buf.readIntLE() / 1000000.0);
             } else {
                 decodeTag(position, buf, tag);
             }
@@ -293,7 +295,7 @@ public class GalileoProtocolDecoder extends BaseProtocolDecoder {
             positions.add(position);
         }
 
-        sendReply(channel, buf.readUnsignedShort());
+        sendReply(channel, buf.readUnsignedShortLE());
 
         for (Position p : positions) {
             p.setDeviceId(deviceSession.getDeviceId());
diff --git a/src/org/traccar/protocol/GalileoProtocolEncoder.java b/src/org/traccar/protocol/GalileoProtocolEncoder.java
index cb6028abb..47fbc3f9c 100644
--- a/src/org/traccar/protocol/GalileoProtocolEncoder.java
+++ b/src/org/traccar/protocol/GalileoProtocolEncoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Anton Tananaev (anton@traccar.org)
+ * Copyright 2017 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,39 +15,38 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.buffer.ChannelBuffer;
-import org.jboss.netty.buffer.ChannelBuffers;
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
 import org.traccar.BaseProtocolEncoder;
 import org.traccar.helper.Checksum;
 import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
-import java.nio.ByteOrder;
 import java.nio.charset.StandardCharsets;
 
 public class GalileoProtocolEncoder extends BaseProtocolEncoder {
 
-    private ChannelBuffer encodeText(String uniqueId, String text) {
+    private ByteBuf encodeText(String uniqueId, String text) {
 
-        ChannelBuffer buf = ChannelBuffers.dynamicBuffer(ByteOrder.LITTLE_ENDIAN, 256);
+        ByteBuf buf = Unpooled.buffer(256);
 
         buf.writeByte(0x01);
-        buf.writeShort(uniqueId.length() + text.length() + 11); // TODO
+        buf.writeShortLE(uniqueId.length() + text.length() + 11); // TODO
 
         buf.writeByte(0x03); // imei tag
         buf.writeBytes(uniqueId.getBytes(StandardCharsets.US_ASCII));
 
         buf.writeByte(0x04); // device id tag
-        buf.writeShort(0); // not needed if imei provided
+        buf.writeShortLE(0); // not needed if imei provided
 
         buf.writeByte(0xE0); // index tag
-        buf.writeInt(0); // index
+        buf.writeIntLE(0); // index
 
         buf.writeByte(0xE1); // command text tag
         buf.writeByte(text.length());
         buf.writeBytes(text.getBytes(StandardCharsets.US_ASCII));
 
-        buf.writeShort(Checksum.crc16(Checksum.CRC16_MODBUS, buf.toByteBuffer(0, buf.writerIndex())));
+        buf.writeShortLE(Checksum.crc16(Checksum.CRC16_MODBUS, buf.nioBuffer(0, buf.writerIndex())));
 
         return buf;
     }
diff --git a/src/org/traccar/protocol/GatorProtocol.java b/src/org/traccar/protocol/GatorProtocol.java
index 7fa4854d3..531f1238c 100644
--- a/src/org/traccar/protocol/GatorProtocol.java
+++ b/src/org/traccar/protocol/GatorProtocol.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 - 2016 Anton Tananaev (anton@traccar.org)
+ * Copyright 2015 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,11 +15,9 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.bootstrap.ConnectionlessBootstrap;
-import org.jboss.netty.bootstrap.ServerBootstrap;
-import org.jboss.netty.channel.ChannelPipeline;
-import org.jboss.netty.handler.codec.frame.LengthFieldBasedFrameDecoder;
+import io.netty.handler.codec.LengthFieldBasedFrameDecoder;
 import org.traccar.BaseProtocol;
+import org.traccar.PipelineBuilder;
 import org.traccar.TrackerServer;
 
 import java.util.List;
@@ -32,16 +30,16 @@ public class GatorProtocol extends BaseProtocol {
 
     @Override
     public void initTrackerServers(List<TrackerServer> serverList) {
-        serverList.add(new TrackerServer(new ServerBootstrap(), getName()) {
+        serverList.add(new TrackerServer(false, getName()) {
             @Override
-            protected void addSpecificHandlers(ChannelPipeline pipeline) {
+            protected void addProtocolHandlers(PipelineBuilder pipeline) {
                 pipeline.addLast("frameDecoder", new LengthFieldBasedFrameDecoder(1024, 3, 2));
                 pipeline.addLast("objectDecoder", new GatorProtocolDecoder(GatorProtocol.this));
             }
         });
-        serverList.add(new TrackerServer(new ConnectionlessBootstrap(), getName()) {
+        serverList.add(new TrackerServer(true, getName()) {
             @Override
-            protected void addSpecificHandlers(ChannelPipeline pipeline) {
+            protected void addProtocolHandlers(PipelineBuilder pipeline) {
                 pipeline.addLast("objectDecoder", new GatorProtocolDecoder(GatorProtocol.this));
             }
         });
diff --git a/src/org/traccar/protocol/GatorProtocolDecoder.java b/src/org/traccar/protocol/GatorProtocolDecoder.java
index b38214457..5841f6fad 100644
--- a/src/org/traccar/protocol/GatorProtocolDecoder.java
+++ b/src/org/traccar/protocol/GatorProtocolDecoder.java
@@ -15,11 +15,12 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.buffer.ChannelBuffer;
-import org.jboss.netty.buffer.ChannelBuffers;
-import org.jboss.netty.channel.Channel;
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.Channel;
 import org.traccar.BaseProtocolDecoder;
 import org.traccar.DeviceSession;
+import org.traccar.NetworkMessage;
 import org.traccar.helper.BcdUtil;
 import org.traccar.helper.DateBuilder;
 import org.traccar.helper.UnitsConverter;
@@ -58,7 +59,7 @@ public class GatorProtocolDecoder extends BaseProtocolDecoder {
 
     private void sendResponse(Channel channel, SocketAddress remoteAddress, byte calibration) {
         if (channel != null) {
-            ChannelBuffer response = ChannelBuffers.dynamicBuffer();
+            ByteBuf response = Unpooled.buffer();
             response.writeByte(0x24); response.writeByte(0x24); // header
             response.writeByte(MSG_HEARTBEAT); // size
             response.writeShort(5);
@@ -67,7 +68,7 @@ public class GatorProtocolDecoder extends BaseProtocolDecoder {
             response.writeByte(0); // slave order
             response.writeByte(1); // calibration
             response.writeByte(0x0D);
-            channel.write(response, remoteAddress);
+            channel.write(new NetworkMessage(response, remoteAddress));
         }
     }
 
@@ -75,7 +76,7 @@ public class GatorProtocolDecoder extends BaseProtocolDecoder {
     protected Object decode(
             Channel channel, SocketAddress remoteAddress, Object msg) throws Exception {
 
-        ChannelBuffer buf = (ChannelBuffer) msg;
+        ByteBuf buf = (ByteBuf) msg;
 
         buf.skipBytes(2); // header
         int type = buf.readUnsignedByte();
diff --git a/src/org/traccar/protocol/GenxProtocol.java b/src/org/traccar/protocol/GenxProtocol.java
index 2b5b1a43d..2c3c4f7a0 100644
--- a/src/org/traccar/protocol/GenxProtocol.java
+++ b/src/org/traccar/protocol/GenxProtocol.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Anton Tananaev (anton@traccar.org)
+ * Copyright 2017 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,11 +15,10 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.bootstrap.ServerBootstrap;
-import org.jboss.netty.channel.ChannelPipeline;
-import org.jboss.netty.handler.codec.frame.LineBasedFrameDecoder;
-import org.jboss.netty.handler.codec.string.StringDecoder;
+import io.netty.handler.codec.LineBasedFrameDecoder;
+import io.netty.handler.codec.string.StringDecoder;
 import org.traccar.BaseProtocol;
+import org.traccar.PipelineBuilder;
 import org.traccar.TrackerServer;
 
 import java.util.List;
@@ -32,9 +31,9 @@ public class GenxProtocol extends BaseProtocol {
 
     @Override
     public void initTrackerServers(List<TrackerServer> serverList) {
-        serverList.add(new TrackerServer(new ServerBootstrap(), getName()) {
+        serverList.add(new TrackerServer(false, getName()) {
             @Override
-            protected void addSpecificHandlers(ChannelPipeline pipeline) {
+            protected void addProtocolHandlers(PipelineBuilder pipeline) {
                 pipeline.addLast("frameDecoder", new LineBasedFrameDecoder(1024));
                 pipeline.addLast("stringDecoder", new StringDecoder());
                 pipeline.addLast("objectDecoder", new GenxProtocolDecoder(GenxProtocol.this));
diff --git a/src/org/traccar/protocol/GenxProtocolDecoder.java b/src/org/traccar/protocol/GenxProtocolDecoder.java
index d4a348ce1..399a42109 100644
--- a/src/org/traccar/protocol/GenxProtocolDecoder.java
+++ b/src/org/traccar/protocol/GenxProtocolDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Anton Tananaev (anton@traccar.org)
+ * Copyright 2017 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,7 +15,7 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.channel.Channel;
+import io.netty.channel.Channel;
 import org.traccar.BaseProtocolDecoder;
 import org.traccar.Context;
 import org.traccar.DeviceSession;
diff --git a/src/org/traccar/protocol/Gl100Protocol.java b/src/org/traccar/protocol/Gl100Protocol.java
index 0fd18d44f..90beab23a 100644
--- a/src/org/traccar/protocol/Gl100Protocol.java
+++ b/src/org/traccar/protocol/Gl100Protocol.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 Anton Tananaev (anton@traccar.org)
+ * Copyright 2015 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,13 +15,11 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.bootstrap.ConnectionlessBootstrap;
-import org.jboss.netty.bootstrap.ServerBootstrap;
-import org.jboss.netty.channel.ChannelPipeline;
-import org.jboss.netty.handler.codec.string.StringDecoder;
-import org.jboss.netty.handler.codec.string.StringEncoder;
+import io.netty.handler.codec.string.StringDecoder;
+import io.netty.handler.codec.string.StringEncoder;
 import org.traccar.BaseProtocol;
 import org.traccar.CharacterDelimiterFrameDecoder;
+import org.traccar.PipelineBuilder;
 import org.traccar.TrackerServer;
 
 import java.util.List;
@@ -34,18 +32,18 @@ public class Gl100Protocol extends BaseProtocol {
 
     @Override
     public void initTrackerServers(List<TrackerServer> serverList) {
-        serverList.add(new TrackerServer(new ServerBootstrap(), getName()) {
+        serverList.add(new TrackerServer(false, getName()) {
             @Override
-            protected void addSpecificHandlers(ChannelPipeline pipeline) {
+            protected void addProtocolHandlers(PipelineBuilder pipeline) {
                 pipeline.addLast("frameDecoder", new CharacterDelimiterFrameDecoder(1024, '\0'));
                 pipeline.addLast("stringEncoder", new StringEncoder());
                 pipeline.addLast("stringDecoder", new StringDecoder());
                 pipeline.addLast("objectDecoder", new Gl100ProtocolDecoder(Gl100Protocol.this));
             }
         });
-        serverList.add(new TrackerServer(new ConnectionlessBootstrap(), getName()) {
+        serverList.add(new TrackerServer(true, getName()) {
             @Override
-            protected void addSpecificHandlers(ChannelPipeline pipeline) {
+            protected void addProtocolHandlers(PipelineBuilder pipeline) {
                 pipeline.addLast("stringEncoder", new StringEncoder());
                 pipeline.addLast("stringDecoder", new StringDecoder());
                 pipeline.addLast("objectDecoder", new Gl100ProtocolDecoder(Gl100Protocol.this));
diff --git a/src/org/traccar/protocol/Gl100ProtocolDecoder.java b/src/org/traccar/protocol/Gl100ProtocolDecoder.java
index 405090695..13ed7120e 100644
--- a/src/org/traccar/protocol/Gl100ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Gl100ProtocolDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012 - 2015 Anton Tananaev (anton@traccar.org)
+ * Copyright 2012 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,9 +15,10 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.channel.Channel;
+import io.netty.channel.Channel;
 import org.traccar.BaseProtocolDecoder;
 import org.traccar.DeviceSession;
+import org.traccar.NetworkMessage;
 import org.traccar.helper.Parser;
 import org.traccar.helper.PatternBuilder;
 import org.traccar.model.Position;
@@ -64,7 +65,7 @@ public class Gl100ProtocolDecoder extends BaseProtocolDecoder {
             String response = "+RESP:GTHBD,GPRS ACTIVE,";
             response += sentence.substring(9, sentence.lastIndexOf(','));
             response += '\0';
-            channel.write(response); // heartbeat response
+            channel.write(new NetworkMessage(response, remoteAddress)); // heartbeat response
         }
 
         Parser parser = new Parser(PATTERN, sentence);
diff --git a/src/org/traccar/protocol/GlobalSatProtocol.java b/src/org/traccar/protocol/GlobalSatProtocol.java
index f3d07fc96..dddf07d55 100644
--- a/src/org/traccar/protocol/GlobalSatProtocol.java
+++ b/src/org/traccar/protocol/GlobalSatProtocol.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 Anton Tananaev (anton@traccar.org)
+ * Copyright 2015 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,12 +15,11 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.bootstrap.ServerBootstrap;
-import org.jboss.netty.channel.ChannelPipeline;
-import org.jboss.netty.handler.codec.string.StringDecoder;
-import org.jboss.netty.handler.codec.string.StringEncoder;
+import io.netty.handler.codec.string.StringDecoder;
+import io.netty.handler.codec.string.StringEncoder;
 import org.traccar.BaseProtocol;
 import org.traccar.CharacterDelimiterFrameDecoder;
+import org.traccar.PipelineBuilder;
 import org.traccar.TrackerServer;
 
 import java.util.List;
@@ -33,9 +32,9 @@ public class GlobalSatProtocol extends BaseProtocol {
 
     @Override
     public void initTrackerServers(List<TrackerServer> serverList) {
-        serverList.add(new TrackerServer(new ServerBootstrap(), getName()) {
+        serverList.add(new TrackerServer(false, getName()) {
             @Override
-            protected void addSpecificHandlers(ChannelPipeline pipeline) {
+            protected void addProtocolHandlers(PipelineBuilder pipeline) {
                 pipeline.addLast("frameDecoder", new CharacterDelimiterFrameDecoder(1024, '!'));
                 pipeline.addLast("stringEncoder", new StringEncoder());
                 pipeline.addLast("stringDecoder", new StringDecoder());
diff --git a/src/org/traccar/protocol/GlobalSatProtocolDecoder.java b/src/org/traccar/protocol/GlobalSatProtocolDecoder.java
index 4361e0c2f..dd1ede9a4 100644
--- a/src/org/traccar/protocol/GlobalSatProtocolDecoder.java
+++ b/src/org/traccar/protocol/GlobalSatProtocolDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2013 - 2014 Anton Tananaev (anton@traccar.org)
+ * Copyright 2013 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,10 +15,11 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.channel.Channel;
+import io.netty.channel.Channel;
 import org.traccar.BaseProtocolDecoder;
 import org.traccar.Context;
 import org.traccar.DeviceSession;
+import org.traccar.NetworkMessage;
 import org.traccar.helper.DateBuilder;
 import org.traccar.helper.Parser;
 import org.traccar.helper.PatternBuilder;
@@ -51,7 +52,7 @@ public class GlobalSatProtocolDecoder extends BaseProtocolDecoder {
     private Position decodeOriginal(Channel channel, SocketAddress remoteAddress, String sentence) {
 
         if (channel != null) {
-            channel.write("ACK\r");
+            channel.write(new NetworkMessage("ACK\r", remoteAddress));
         }
 
         String format;
diff --git a/src/org/traccar/protocol/GnxProtocol.java b/src/org/traccar/protocol/GnxProtocol.java
index 84af24000..985f200eb 100644
--- a/src/org/traccar/protocol/GnxProtocol.java
+++ b/src/org/traccar/protocol/GnxProtocol.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 Anton Tananaev (anton@traccar.org)
+ * Copyright 2016 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,12 +15,11 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.bootstrap.ServerBootstrap;
-import org.jboss.netty.channel.ChannelPipeline;
-import org.jboss.netty.handler.codec.string.StringDecoder;
-import org.jboss.netty.handler.codec.string.StringEncoder;
+import io.netty.handler.codec.string.StringDecoder;
+import io.netty.handler.codec.string.StringEncoder;
 import org.traccar.BaseProtocol;
 import org.traccar.CharacterDelimiterFrameDecoder;
+import org.traccar.PipelineBuilder;
 import org.traccar.TrackerServer;
 
 import java.util.List;
@@ -33,9 +32,9 @@ public class GnxProtocol extends BaseProtocol {
 
     @Override
     public void initTrackerServers(List<TrackerServer> serverList) {
-        serverList.add(new TrackerServer(new ServerBootstrap(), getName()) {
+        serverList.add(new TrackerServer(false, getName()) {
             @Override
-            protected void addSpecificHandlers(ChannelPipeline pipeline) {
+            protected void addProtocolHandlers(PipelineBuilder pipeline) {
                 pipeline.addLast("frameDecoder", new CharacterDelimiterFrameDecoder(1024, "\n\r"));
                 pipeline.addLast("stringDecoder", new StringDecoder());
                 pipeline.addLast("stringEncoder", new StringEncoder());
diff --git a/src/org/traccar/protocol/GnxProtocolDecoder.java b/src/org/traccar/protocol/GnxProtocolDecoder.java
index b3a636d14..36bcba2dc 100644
--- a/src/org/traccar/protocol/GnxProtocolDecoder.java
+++ b/src/org/traccar/protocol/GnxProtocolDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 Anton Tananaev (anton@traccar.org)
+ * Copyright 2016 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,7 +15,7 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.channel.Channel;
+import io.netty.channel.Channel;
 import org.traccar.BaseProtocolDecoder;
 import org.traccar.DeviceSession;
 import org.traccar.helper.Parser;
diff --git a/src/org/traccar/protocol/GoSafeProtocol.java b/src/org/traccar/protocol/GoSafeProtocol.java
index bfd473df9..e4c6cc66f 100644
--- a/src/org/traccar/protocol/GoSafeProtocol.java
+++ b/src/org/traccar/protocol/GoSafeProtocol.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 Anton Tananaev (anton@traccar.org)
+ * Copyright 2015 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,12 +15,11 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.bootstrap.ServerBootstrap;
-import org.jboss.netty.channel.ChannelPipeline;
-import org.jboss.netty.handler.codec.string.StringDecoder;
-import org.jboss.netty.handler.codec.string.StringEncoder;
+import io.netty.handler.codec.string.StringDecoder;
+import io.netty.handler.codec.string.StringEncoder;
 import org.traccar.BaseProtocol;
 import org.traccar.CharacterDelimiterFrameDecoder;
+import org.traccar.PipelineBuilder;
 import org.traccar.TrackerServer;
 
 import java.util.List;
@@ -33,9 +32,9 @@ public class GoSafeProtocol extends BaseProtocol {
 
     @Override
     public void initTrackerServers(List<TrackerServer> serverList) {
-        serverList.add(new TrackerServer(new ServerBootstrap(), getName()) {
+        serverList.add(new TrackerServer(false, getName()) {
             @Override
-            protected void addSpecificHandlers(ChannelPipeline pipeline) {
+            protected void addProtocolHandlers(PipelineBuilder pipeline) {
                 pipeline.addLast("frameDecoder", new CharacterDelimiterFrameDecoder(1024, '#'));
                 pipeline.addLast("stringEncoder", new StringEncoder());
                 pipeline.addLast("stringDecoder", new StringDecoder());
diff --git a/src/org/traccar/protocol/GoSafeProtocolDecoder.java b/src/org/traccar/protocol/GoSafeProtocolDecoder.java
index ae00ad71a..38224f16d 100644
--- a/src/org/traccar/protocol/GoSafeProtocolDecoder.java
+++ b/src/org/traccar/protocol/GoSafeProtocolDecoder.java
@@ -15,9 +15,10 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.channel.Channel;
+import io.netty.channel.Channel;
 import org.traccar.BaseProtocolDecoder;
 import org.traccar.DeviceSession;
+import org.traccar.NetworkMessage;
 import org.traccar.helper.BitUtil;
 import org.traccar.helper.DateBuilder;
 import org.traccar.helper.Parser;
@@ -205,7 +206,7 @@ public class GoSafeProtocolDecoder extends BaseProtocolDecoder {
             Channel channel, SocketAddress remoteAddress, Object msg) throws Exception {
 
         if (channel != null) {
-            channel.write("1234");
+            channel.write(new NetworkMessage("1234", remoteAddress));
         }
 
         String sentence = (String) msg;
diff --git a/src/org/traccar/protocol/GotopProtocol.java b/src/org/traccar/protocol/GotopProtocol.java
index 5d522adf5..272c38cd0 100644
--- a/src/org/traccar/protocol/GotopProtocol.java
+++ b/src/org/traccar/protocol/GotopProtocol.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 Anton Tananaev (anton@traccar.org)
+ * Copyright 2015 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,12 +15,11 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.bootstrap.ServerBootstrap;
-import org.jboss.netty.channel.ChannelPipeline;
-import org.jboss.netty.handler.codec.string.StringDecoder;
-import org.jboss.netty.handler.codec.string.StringEncoder;
+import io.netty.handler.codec.string.StringDecoder;
+import io.netty.handler.codec.string.StringEncoder;
 import org.traccar.BaseProtocol;
 import org.traccar.CharacterDelimiterFrameDecoder;
+import org.traccar.PipelineBuilder;
 import org.traccar.TrackerServer;
 
 import java.util.List;
@@ -33,9 +32,9 @@ public class GotopProtocol extends BaseProtocol {
 
     @Override
     public void initTrackerServers(List<TrackerServer> serverList) {
-        serverList.add(new TrackerServer(new ServerBootstrap(), getName()) {
+        serverList.add(new TrackerServer(false, getName()) {
             @Override
-            protected void addSpecificHandlers(ChannelPipeline pipeline) {
+            protected void addProtocolHandlers(PipelineBuilder pipeline) {
                 pipeline.addLast("frameDecoder", new CharacterDelimiterFrameDecoder(1024, '#'));
                 pipeline.addLast("stringDecoder", new StringDecoder());
                 pipeline.addLast("stringEncoder", new StringEncoder());
diff --git a/src/org/traccar/protocol/GotopProtocolDecoder.java b/src/org/traccar/protocol/GotopProtocolDecoder.java
index 29e8d87dd..728c2a8d6 100644
--- a/src/org/traccar/protocol/GotopProtocolDecoder.java
+++ b/src/org/traccar/protocol/GotopProtocolDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2013 - 2015 Anton Tananaev (anton@traccar.org)
+ * Copyright 2013 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,7 +15,7 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.channel.Channel;
+import io.netty.channel.Channel;
 import org.traccar.BaseProtocolDecoder;
 import org.traccar.DeviceSession;
 import org.traccar.helper.Parser;
diff --git a/src/org/traccar/protocol/Gps056FrameDecoder.java b/src/org/traccar/protocol/Gps056FrameDecoder.java
index 4ce83dc0a..7cfd54c4e 100644
--- a/src/org/traccar/protocol/Gps056FrameDecoder.java
+++ b/src/org/traccar/protocol/Gps056FrameDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Anton Tananaev (anton@traccar.org)
+ * Copyright 2017 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,26 +15,26 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.buffer.ChannelBuffer;
-import org.jboss.netty.channel.Channel;
-import org.jboss.netty.channel.ChannelHandlerContext;
-import org.jboss.netty.handler.codec.frame.FrameDecoder;
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelHandlerContext;
+import org.traccar.BaseFrameDecoder;
 
 import java.nio.charset.StandardCharsets;
 
-public class Gps056FrameDecoder extends FrameDecoder {
+public class Gps056FrameDecoder extends BaseFrameDecoder {
 
     private static final int MESSAGE_HEADER = 4;
 
     @Override
     protected Object decode(
-            ChannelHandlerContext ctx, Channel channel, ChannelBuffer buf) throws Exception {
+            ChannelHandlerContext ctx, Channel channel, ByteBuf buf) throws Exception {
 
         if (buf.readableBytes() >= MESSAGE_HEADER) {
             int length = Integer.parseInt(buf.toString(2, 2, StandardCharsets.US_ASCII)) + 5;
             if (buf.readableBytes() >= length) {
-                ChannelBuffer frame = buf.readBytes(length);
-                while (buf.readable() && buf.getUnsignedByte(buf.readerIndex()) != '$') {
+                ByteBuf frame = buf.readBytes(length);
+                while (buf.isReadable() && buf.getUnsignedByte(buf.readerIndex()) != '$') {
                     buf.readByte();
                 }
                 return frame;
diff --git a/src/org/traccar/protocol/Gps056Protocol.java b/src/org/traccar/protocol/Gps056Protocol.java
index 33c190ad2..f5122830d 100644
--- a/src/org/traccar/protocol/Gps056Protocol.java
+++ b/src/org/traccar/protocol/Gps056Protocol.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Anton Tananaev (anton@traccar.org)
+ * Copyright 2017 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,9 +15,8 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.bootstrap.ServerBootstrap;
-import org.jboss.netty.channel.ChannelPipeline;
 import org.traccar.BaseProtocol;
+import org.traccar.PipelineBuilder;
 import org.traccar.TrackerServer;
 
 import java.util.List;
@@ -30,9 +29,9 @@ public class Gps056Protocol extends BaseProtocol {
 
     @Override
     public void initTrackerServers(List<TrackerServer> serverList) {
-        serverList.add(new TrackerServer(new ServerBootstrap(), getName()) {
+        serverList.add(new TrackerServer(false, getName()) {
             @Override
-            protected void addSpecificHandlers(ChannelPipeline pipeline) {
+            protected void addProtocolHandlers(PipelineBuilder pipeline) {
                 pipeline.addLast("frameDecoder", new Gps056FrameDecoder());
                 pipeline.addLast("objectDecoder", new Gps056ProtocolDecoder(Gps056Protocol.this));
             }
diff --git a/src/org/traccar/protocol/Gps056ProtocolDecoder.java b/src/org/traccar/protocol/Gps056ProtocolDecoder.java
index ccb389250..d8d63cce2 100644
--- a/src/org/traccar/protocol/Gps056ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Gps056ProtocolDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Anton Tananaev (anton@traccar.org)
+ * Copyright 2017 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,11 +15,12 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.buffer.ChannelBuffer;
-import org.jboss.netty.buffer.ChannelBuffers;
-import org.jboss.netty.channel.Channel;
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.Channel;
 import org.traccar.BaseProtocolDecoder;
 import org.traccar.DeviceSession;
+import org.traccar.NetworkMessage;
 import org.traccar.helper.DateBuilder;
 import org.traccar.helper.UnitsConverter;
 import org.traccar.model.Position;
@@ -33,20 +34,20 @@ public class Gps056ProtocolDecoder extends BaseProtocolDecoder {
         super(protocol);
     }
 
-    private static void sendResponse(Channel channel, String type, String imei, ChannelBuffer content) {
+    private static void sendResponse(Channel channel, String type, String imei, ByteBuf content) {
         if (channel != null) {
-            ChannelBuffer response = ChannelBuffers.dynamicBuffer();
+            ByteBuf response = Unpooled.buffer();
             String header = "*" + type + imei;
             response.writeBytes(header.getBytes(StandardCharsets.US_ASCII));
             if (content != null) {
                 response.writeBytes(content);
             }
             response.writeByte('#');
-            channel.write(response);
+            channel.write(new NetworkMessage(response, channel.remoteAddress()));
         }
     }
 
-    private static double decodeCoordinate(ChannelBuffer buf) {
+    private static double decodeCoordinate(ByteBuf buf) {
         double degrees = buf.getUnsignedShort(buf.readerIndex()) / 100;
         double minutes = buf.readUnsignedShort() % 100 + buf.readUnsignedShort() * 0.0001;
         degrees += minutes / 60;
@@ -57,12 +58,12 @@ public class Gps056ProtocolDecoder extends BaseProtocolDecoder {
         return degrees;
     }
 
-    private static void decodeStatus(ChannelBuffer buf, Position position) {
+    private static void decodeStatus(ByteBuf buf, Position position) {
 
         position.set(Position.KEY_INPUT, buf.readUnsignedByte());
         position.set(Position.KEY_OUTPUT, buf.readUnsignedByte());
 
-        position.set(Position.PREFIX_ADC + 1, ChannelBuffers.swapShort(buf.readShort()) * 5.06); // mV
+        position.set(Position.PREFIX_ADC + 1, buf.readShortLE() * 5.06); // mV
 
         position.set(Position.KEY_SATELLITES, buf.readUnsignedByte());
         position.set(Position.KEY_RSSI, buf.readUnsignedByte());
@@ -73,7 +74,7 @@ public class Gps056ProtocolDecoder extends BaseProtocolDecoder {
     protected Object decode(
             Channel channel, SocketAddress remoteAddress, Object msg) throws Exception {
 
-        ChannelBuffer buf = (ChannelBuffer) msg;
+        ByteBuf buf = (ByteBuf) msg;
 
         buf.skipBytes(2); // header
         buf.skipBytes(2); // length
@@ -89,7 +90,7 @@ public class Gps056ProtocolDecoder extends BaseProtocolDecoder {
         if (type.startsWith("LOGN")) {
 
             sendResponse(channel, "LGSA" + type.substring(4), imei,
-                    ChannelBuffers.copiedBuffer("1", StandardCharsets.US_ASCII));
+                    Unpooled.copiedBuffer("1", StandardCharsets.US_ASCII));
 
         } else if (type.startsWith("GPSL")) {
 
diff --git a/src/org/traccar/protocol/GpsGateProtocol.java b/src/org/traccar/protocol/GpsGateProtocol.java
index c7dc2c4f3..4685e40b7 100644
--- a/src/org/traccar/protocol/GpsGateProtocol.java
+++ b/src/org/traccar/protocol/GpsGateProtocol.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 - 2016 Anton Tananaev (anton@traccar.org)
+ * Copyright 2015 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,12 +15,11 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.bootstrap.ServerBootstrap;
-import org.jboss.netty.channel.ChannelPipeline;
-import org.jboss.netty.handler.codec.string.StringDecoder;
-import org.jboss.netty.handler.codec.string.StringEncoder;
+import io.netty.handler.codec.string.StringDecoder;
+import io.netty.handler.codec.string.StringEncoder;
 import org.traccar.BaseProtocol;
 import org.traccar.CharacterDelimiterFrameDecoder;
+import org.traccar.PipelineBuilder;
 import org.traccar.TrackerServer;
 
 import java.util.List;
@@ -33,9 +32,9 @@ public class GpsGateProtocol extends BaseProtocol {
 
     @Override
     public void initTrackerServers(List<TrackerServer> serverList) {
-        serverList.add(new TrackerServer(new ServerBootstrap(), getName()) {
+        serverList.add(new TrackerServer(false, getName()) {
             @Override
-            protected void addSpecificHandlers(ChannelPipeline pipeline) {
+            protected void addProtocolHandlers(PipelineBuilder pipeline) {
                 pipeline.addLast("frameDecoder", new CharacterDelimiterFrameDecoder(1024, "\0", "\n", "\r\n"));
                 pipeline.addLast("stringEncoder", new StringEncoder());
                 pipeline.addLast("stringDecoder", new StringDecoder());
diff --git a/src/org/traccar/protocol/GpsGateProtocolDecoder.java b/src/org/traccar/protocol/GpsGateProtocolDecoder.java
index 5c7096276..b4357ff64 100644
--- a/src/org/traccar/protocol/GpsGateProtocolDecoder.java
+++ b/src/org/traccar/protocol/GpsGateProtocolDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2013 - 2016 Anton Tananaev (anton@traccar.org)
+ * Copyright 2013 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,9 +15,10 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.channel.Channel;
+import io.netty.channel.Channel;
 import org.traccar.BaseProtocolDecoder;
 import org.traccar.DeviceSession;
+import org.traccar.NetworkMessage;
 import org.traccar.helper.Checksum;
 import org.traccar.helper.DateBuilder;
 import org.traccar.helper.Parser;
@@ -65,9 +66,9 @@ public class GpsGateProtocolDecoder extends BaseProtocolDecoder {
             .any()
             .compile();
 
-    private void send(Channel channel, String message) {
+    private void send(Channel channel, SocketAddress remoteAddress, String message) {
         if (channel != null) {
-            channel.write(message + Checksum.nmea(message) + "\r\n");
+            channel.write(new NetworkMessage(message + Checksum.nmea(message) + "\r\n", remoteAddress));
         }
     }
 
@@ -79,7 +80,6 @@ public class GpsGateProtocolDecoder extends BaseProtocolDecoder {
 
         if (sentence.startsWith("$FRLIN,")) {
 
-            // Login
             int beginIndex = sentence.indexOf(',', 7);
             if (beginIndex != -1) {
                 beginIndex += 1;
@@ -89,22 +89,21 @@ public class GpsGateProtocolDecoder extends BaseProtocolDecoder {
                     DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, imei);
                     if (deviceSession != null) {
                         if (channel != null) {
-                            send(channel, "$FRSES," + channel.getId());
+                            send(channel, remoteAddress, "$FRSES," + channel.id().asShortText());
                         }
                     } else {
-                        send(channel, "$FRERR,AuthError,Unknown device");
+                        send(channel, remoteAddress, "$FRERR,AuthError,Unknown device");
                     }
                 } else {
-                    send(channel, "$FRERR,AuthError,Parse error");
+                    send(channel, remoteAddress, "$FRERR,AuthError,Parse error");
                 }
             } else {
-                send(channel, "$FRERR,AuthError,Parse error");
+                send(channel, remoteAddress, "$FRERR,AuthError,Parse error");
             }
 
         } else if (sentence.startsWith("$FRVER,")) {
 
-            // Version check
-            send(channel, "$FRVER,1,0,GpsGate Server 1.0");
+            send(channel, remoteAddress, "$FRVER,1,0,GpsGate Server 1.0");
 
         } else if (sentence.startsWith("$GPRMC,")) {
 
diff --git a/src/org/traccar/protocol/GpsMarkerProtocol.java b/src/org/traccar/protocol/GpsMarkerProtocol.java
index 5c64d16b2..0655d2c88 100644
--- a/src/org/traccar/protocol/GpsMarkerProtocol.java
+++ b/src/org/traccar/protocol/GpsMarkerProtocol.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 Anton Tananaev (anton@traccar.org)
+ * Copyright 2015 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,12 +15,11 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.bootstrap.ServerBootstrap;
-import org.jboss.netty.channel.ChannelPipeline;
-import org.jboss.netty.handler.codec.string.StringDecoder;
-import org.jboss.netty.handler.codec.string.StringEncoder;
+import io.netty.handler.codec.string.StringDecoder;
+import io.netty.handler.codec.string.StringEncoder;
 import org.traccar.BaseProtocol;
 import org.traccar.CharacterDelimiterFrameDecoder;
+import org.traccar.PipelineBuilder;
 import org.traccar.TrackerServer;
 
 import java.util.List;
@@ -33,9 +32,9 @@ public class GpsMarkerProtocol extends BaseProtocol {
 
     @Override
     public void initTrackerServers(List<TrackerServer> serverList) {
-        serverList.add(new TrackerServer(new ServerBootstrap(), getName()) {
+        serverList.add(new TrackerServer(false, getName()) {
             @Override
-            protected void addSpecificHandlers(ChannelPipeline pipeline) {
+            protected void addProtocolHandlers(PipelineBuilder pipeline) {
                 pipeline.addLast("frameDecoder", new CharacterDelimiterFrameDecoder(1024, "\r"));
                 pipeline.addLast("stringDecoder", new StringDecoder());
                 pipeline.addLast("stringEncoder", new StringEncoder());
diff --git a/src/org/traccar/protocol/GpsMarkerProtocolDecoder.java b/src/org/traccar/protocol/GpsMarkerProtocolDecoder.java
index ca5bdcbed..a6e39e353 100644
--- a/src/org/traccar/protocol/GpsMarkerProtocolDecoder.java
+++ b/src/org/traccar/protocol/GpsMarkerProtocolDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 - 2016 Anton Tananaev (anton@traccar.org)
+ * Copyright 2015 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,7 +15,7 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.channel.Channel;
+import io.netty.channel.Channel;
 import org.traccar.BaseProtocolDecoder;
 import org.traccar.DeviceSession;
 import org.traccar.helper.Parser;
diff --git a/src/org/traccar/protocol/GpsmtaProtocol.java b/src/org/traccar/protocol/GpsmtaProtocol.java
index 2d1181bec..b2720cb8a 100644
--- a/src/org/traccar/protocol/GpsmtaProtocol.java
+++ b/src/org/traccar/protocol/GpsmtaProtocol.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 Anton Tananaev (anton@traccar.org)
+ * Copyright 2015 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,11 +15,10 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.bootstrap.ConnectionlessBootstrap;
-import org.jboss.netty.channel.ChannelPipeline;
-import org.jboss.netty.handler.codec.string.StringDecoder;
-import org.jboss.netty.handler.codec.string.StringEncoder;
+import io.netty.handler.codec.string.StringDecoder;
+import io.netty.handler.codec.string.StringEncoder;
 import org.traccar.BaseProtocol;
+import org.traccar.PipelineBuilder;
 import org.traccar.TrackerServer;
 
 import java.util.List;
@@ -32,9 +31,9 @@ public class GpsmtaProtocol extends BaseProtocol {
 
     @Override
     public void initTrackerServers(List<TrackerServer> serverList) {
-        serverList.add(new TrackerServer(new ConnectionlessBootstrap(), getName()) {
+        serverList.add(new TrackerServer(true, getName()) {
             @Override
-            protected void addSpecificHandlers(ChannelPipeline pipeline) {
+            protected void addProtocolHandlers(PipelineBuilder pipeline) {
                 pipeline.addLast("stringEncoder", new StringEncoder());
                 pipeline.addLast("stringDecoder", new StringDecoder());
                 pipeline.addLast("objectDecoder", new GpsmtaProtocolDecoder(GpsmtaProtocol.this));
diff --git a/src/org/traccar/protocol/GpsmtaProtocolDecoder.java b/src/org/traccar/protocol/GpsmtaProtocolDecoder.java
index c71162078..a4e732ed9 100644
--- a/src/org/traccar/protocol/GpsmtaProtocolDecoder.java
+++ b/src/org/traccar/protocol/GpsmtaProtocolDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 Anton Tananaev (anton@traccar.org)
+ * Copyright 2015 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,9 +15,10 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.channel.Channel;
+import io.netty.channel.Channel;
 import org.traccar.BaseProtocolDecoder;
 import org.traccar.DeviceSession;
+import org.traccar.NetworkMessage;
 import org.traccar.helper.Parser;
 import org.traccar.helper.PatternBuilder;
 import org.traccar.model.Position;
@@ -81,7 +82,7 @@ public class GpsmtaProtocolDecoder extends BaseProtocolDecoder {
         position.set(Position.KEY_CHARGE, parser.nextInt(0) == 1);
 
         if (channel != null) {
-            channel.write(time, remoteAddress);
+            channel.write(new NetworkMessage(time, remoteAddress));
         }
 
         return position;
diff --git a/src/org/traccar/protocol/GranitFrameDecoder.java b/src/org/traccar/protocol/GranitFrameDecoder.java
index 7e8f4a3f5..5e555fb15 100644
--- a/src/org/traccar/protocol/GranitFrameDecoder.java
+++ b/src/org/traccar/protocol/GranitFrameDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 Anton Tananaev (anton@traccar.org)
+ * Copyright 2016 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,29 +15,29 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.buffer.ChannelBuffer;
-import org.jboss.netty.channel.Channel;
-import org.jboss.netty.channel.ChannelHandlerContext;
-import org.jboss.netty.handler.codec.frame.FrameDecoder;
-import org.traccar.helper.StringFinder;
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelHandlerContext;
+import org.traccar.BaseFrameDecoder;
+import org.traccar.helper.BufferUtil;
 
-public class GranitFrameDecoder extends FrameDecoder {
+public class GranitFrameDecoder extends BaseFrameDecoder {
 
     @Override
     protected Object decode(
-            ChannelHandlerContext ctx, Channel channel, ChannelBuffer buf) throws Exception {
+            ChannelHandlerContext ctx, Channel channel, ByteBuf buf) throws Exception {
 
-        int indexEnd = buf.indexOf(buf.readerIndex(), buf.writerIndex(), new StringFinder("\r\n"));
+        int indexEnd = BufferUtil.indexOf("\r\n", buf);
         if (indexEnd != -1) {
-            int indexTilde = buf.indexOf(buf.readerIndex(), buf.writerIndex(), new StringFinder("~"));
+            int indexTilde = buf.indexOf(buf.readerIndex(), buf.writerIndex(), (byte) '~');
             if (indexTilde != -1 && indexTilde < indexEnd) {
-                int length = buf.getUnsignedShort(indexTilde + 1);
-                indexEnd = buf.indexOf(indexTilde + 2 + length, buf.writerIndex(), new StringFinder("\r\n"));
+                int length = buf.getUnsignedShortLE(indexTilde + 1);
+                indexEnd = BufferUtil.indexOf("\r\n", buf, indexTilde + 2 + length, buf.writerIndex());
                 if (indexEnd == -1) {
                     return null;
                 }
             }
-            ChannelBuffer frame = buf.readBytes(indexEnd - buf.readerIndex());
+            ByteBuf frame = buf.readBytes(indexEnd - buf.readerIndex());
             buf.skipBytes(2);
             return frame;
         }
diff --git a/src/org/traccar/protocol/GranitProtocol.java b/src/org/traccar/protocol/GranitProtocol.java
index 32e8e00b0..5855d34ee 100644
--- a/src/org/traccar/protocol/GranitProtocol.java
+++ b/src/org/traccar/protocol/GranitProtocol.java
@@ -1,6 +1,6 @@
 /*
- * Copyright 2016 - 2017 Anton Tananaev (anton@traccar.org)
- * Copyright 2017 Andrey Kunitsyn (andrey@traccar.org)
+ * Copyright 2016 - 2018 Anton Tananaev (anton@traccar.org)
+ * Copyright 2017 - 2018 Andrey Kunitsyn (andrey@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,13 +16,11 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.bootstrap.ServerBootstrap;
-import org.jboss.netty.channel.ChannelPipeline;
 import org.traccar.BaseProtocol;
+import org.traccar.PipelineBuilder;
 import org.traccar.TrackerServer;
 import org.traccar.model.Command;
 
-import java.nio.ByteOrder;
 import java.util.List;
 
 public class GranitProtocol extends BaseProtocol {
@@ -41,16 +39,14 @@ public class GranitProtocol extends BaseProtocol {
 
     @Override
     public void initTrackerServers(List<TrackerServer> serverList) {
-        TrackerServer server = new TrackerServer(new ServerBootstrap(), getName()) {
+        serverList.add(new TrackerServer(false, getName()) {
             @Override
-            protected void addSpecificHandlers(ChannelPipeline pipeline) {
+            protected void addProtocolHandlers(PipelineBuilder pipeline) {
                 pipeline.addLast("frameDecoder", new GranitFrameDecoder());
                 pipeline.addLast("objectEncoder", new GranitProtocolEncoder());
                 pipeline.addLast("objectDecoder", new GranitProtocolDecoder(GranitProtocol.this));
             }
-        };
-        server.setEndianness(ByteOrder.LITTLE_ENDIAN);
-        serverList.add(server);
+        });
     }
 
 }
diff --git a/src/org/traccar/protocol/GranitProtocolDecoder.java b/src/org/traccar/protocol/GranitProtocolDecoder.java
index 50d879bb4..d9e7b62d8 100644
--- a/src/org/traccar/protocol/GranitProtocolDecoder.java
+++ b/src/org/traccar/protocol/GranitProtocolDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 Anton Tananaev (anton@traccar.org)
+ * Copyright 2016 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,19 +15,18 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.buffer.ChannelBuffer;
-import org.jboss.netty.buffer.ChannelBuffers;
-import org.jboss.netty.channel.Channel;
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.Channel;
 import org.traccar.BaseProtocolDecoder;
 import org.traccar.Context;
 import org.traccar.DeviceSession;
+import org.traccar.NetworkMessage;
 import org.traccar.helper.BitUtil;
 import org.traccar.helper.Checksum;
-import org.traccar.helper.StringFinder;
 import org.traccar.model.Position;
 
 import java.net.SocketAddress;
-import java.nio.ByteOrder;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Date;
@@ -50,35 +49,35 @@ public class GranitProtocolDecoder extends BaseProtocolDecoder {
         adc4Ratio = Context.getConfig().getDouble("granit.adc4Ratio", 1);
     }
 
-    public static void appendChecksum(ChannelBuffer buffer, int length) {
+    public static void appendChecksum(ByteBuf buffer, int length) {
         buffer.writeByte('*');
-        int checksum = Checksum.xor(buffer.toByteBuffer(0, length)) & 0xFF;
+        int checksum = Checksum.xor(buffer.nioBuffer(0, length)) & 0xFF;
         String checksumString = String.format("%02X", checksum);
         buffer.writeBytes(checksumString.getBytes(StandardCharsets.US_ASCII));
         buffer.writeByte('\r'); buffer.writeByte('\n');
     }
 
     private static void sendResponseCurrent(Channel channel, int deviceId, long time) {
-        ChannelBuffer response = ChannelBuffers.dynamicBuffer(ByteOrder.LITTLE_ENDIAN, 0);
+        ByteBuf response = Unpooled.buffer(0);
         response.writeBytes("BB+UGRC~".getBytes(StandardCharsets.US_ASCII));
-        response.writeShort(6); // length
+        response.writeShortLE(6); // length
         response.writeInt((int) time);
-        response.writeShort(deviceId);
+        response.writeShortLE(deviceId);
         appendChecksum(response, 16);
-        channel.write(response);
+        channel.write(new NetworkMessage(response, channel.remoteAddress()));
     }
 
     private static void sendResponseArchive(Channel channel, int deviceId, int packNum) {
-        ChannelBuffer response = ChannelBuffers.dynamicBuffer(ByteOrder.LITTLE_ENDIAN, 0);
+        ByteBuf response = Unpooled.buffer(0);
         response.writeBytes("BB+ARCF~".getBytes(StandardCharsets.US_ASCII));
-        response.writeShort(4); // length
-        response.writeShort(packNum);
-        response.writeShort(deviceId);
+        response.writeShortLE(4); // length
+        response.writeShortLE(packNum);
+        response.writeShortLE(deviceId);
         appendChecksum(response, 14);
-        channel.write(response);
+        channel.write(new NetworkMessage(response, channel.remoteAddress()));
     }
 
-    private void decodeStructure(ChannelBuffer buf, Position position) {
+    private void decodeStructure(ByteBuf buf, Position position) {
         short flags = buf.readUnsignedByte();
         position.setValid(BitUtil.check(flags, 7));
         if (BitUtil.check(flags, 1)) {
@@ -93,8 +92,8 @@ public class GranitProtocolDecoder extends BaseProtocolDecoder {
 
         int lonDegrees = buf.readUnsignedByte();
         int latDegrees = buf.readUnsignedByte();
-        int lonMinutes = buf.readUnsignedShort();
-        int latMinutes = buf.readUnsignedShort();
+        int lonMinutes = buf.readUnsignedShortLE();
+        int latMinutes = buf.readUnsignedShortLE();
 
         double latitude = latDegrees + latMinutes / 60000.0;
         double longitude = lonDegrees + lonMinutes / 60000.0;
@@ -119,7 +118,7 @@ public class GranitProtocolDecoder extends BaseProtocolDecoder {
         }
         position.setCourse(course);
 
-        position.set(Position.KEY_DISTANCE, buf.readShort());
+        position.set(Position.KEY_DISTANCE, buf.readShortLE());
 
         int analogIn1 = buf.readUnsignedByte();
         int analogIn2 = buf.readUnsignedByte();
@@ -150,9 +149,9 @@ public class GranitProtocolDecoder extends BaseProtocolDecoder {
     @Override
     protected Object decode(Channel channel, SocketAddress remoteAddress, Object msg) throws Exception {
 
-        ChannelBuffer buf = (ChannelBuffer) msg;
+        ByteBuf buf = (ByteBuf) msg;
 
-        int indexTilde = buf.indexOf(buf.readerIndex(), buf.writerIndex(), new StringFinder("~"));
+        int indexTilde = buf.indexOf(buf.readerIndex(), buf.writerIndex(), (byte) '~');
 
         DeviceSession deviceSession = getDeviceSession(channel, remoteAddress);
 
@@ -175,13 +174,13 @@ public class GranitProtocolDecoder extends BaseProtocolDecoder {
 
         if (header.equals("+RRCB~")) {
 
-            buf.skipBytes(2); //binary length 26
-            int deviceId = buf.readUnsignedShort();
+            buf.skipBytes(2); // binary length 26
+            int deviceId = buf.readUnsignedShortLE();
             deviceSession = getDeviceSession(channel, remoteAddress, String.valueOf(deviceId));
             if (deviceSession == null) {
                 return null;
             }
-            long unixTime = buf.readUnsignedInt();
+            long unixTime = buf.readUnsignedIntLE();
             if (channel != null) {
                 sendResponseCurrent(channel, deviceId, unixTime);
             }
@@ -195,8 +194,8 @@ public class GranitProtocolDecoder extends BaseProtocolDecoder {
 
         } else if (header.equals("+DDAT~")) {
 
-            buf.skipBytes(2); //binary length
-            int deviceId = buf.readUnsignedShort();
+            buf.skipBytes(2); // binary length
+            int deviceId = buf.readUnsignedShortLE();
             deviceSession = getDeviceSession(channel, remoteAddress, String.valueOf(deviceId));
             if (deviceSession == null) {
                 return null;
@@ -206,15 +205,15 @@ public class GranitProtocolDecoder extends BaseProtocolDecoder {
                 return null;
             }
             byte nblocks = buf.readByte();
-            int packNum = buf.readUnsignedShort();
+            int packNum = buf.readUnsignedShortLE();
             if (channel != null) {
                 sendResponseArchive(channel, deviceId, packNum);
             }
             List<Position> positions = new ArrayList<>();
             while (nblocks > 0) {
                 nblocks--;
-                long unixTime = buf.readUnsignedInt();
-                int timeIncrement = buf.getUnsignedShort(buf.readerIndex() + 120);
+                long unixTime = buf.readUnsignedIntLE();
+                int timeIncrement = buf.getUnsignedShortLE(buf.readerIndex() + 120);
                 for (int i = 0; i < 6; i++) {
                     if (buf.getUnsignedByte(buf.readerIndex()) != 0xFE) {
                         Position position = new Position(getProtocolName());
diff --git a/src/org/traccar/protocol/GranitProtocolEncoder.java b/src/org/traccar/protocol/GranitProtocolEncoder.java
index dbfd30ff1..bde267ee6 100644
--- a/src/org/traccar/protocol/GranitProtocolEncoder.java
+++ b/src/org/traccar/protocol/GranitProtocolEncoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 Anton Tananaev (anton@traccar.org)
+ * Copyright 2016 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -13,12 +13,12 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
- package org.traccar.protocol;
+package org.traccar.protocol;
 
 import java.nio.charset.StandardCharsets;
 
-import org.jboss.netty.buffer.ChannelBuffer;
-import org.jboss.netty.buffer.ChannelBuffers;
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
 import org.traccar.BaseProtocolEncoder;
 import org.traccar.helper.Log;
 import org.traccar.model.Command;
@@ -44,7 +44,7 @@ public class GranitProtocolEncoder extends BaseProtocolEncoder {
                 return null;
         }
         if (!commandString.isEmpty()) {
-            ChannelBuffer commandBuf = ChannelBuffers.dynamicBuffer();
+            ByteBuf commandBuf = Unpooled.buffer();
             commandBuf.writeBytes(commandString.getBytes(StandardCharsets.US_ASCII));
             GranitProtocolDecoder.appendChecksum(commandBuf, commandString.length());
             return commandBuf;
diff --git a/src/org/traccar/protocol/Gt02Protocol.java b/src/org/traccar/protocol/Gt02Protocol.java
index 0abd4021b..f44cb3979 100644
--- a/src/org/traccar/protocol/Gt02Protocol.java
+++ b/src/org/traccar/protocol/Gt02Protocol.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 Anton Tananaev (anton@traccar.org)
+ * Copyright 2015 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,9 +15,9 @@
  */
 package org.traccar.protocol;
 
-import io.netty.channel.ChannelPipeline;
 import io.netty.handler.codec.LengthFieldBasedFrameDecoder;
 import org.traccar.BaseProtocol;
+import org.traccar.PipelineBuilder;
 import org.traccar.TrackerServer;
 
 import java.util.List;
@@ -32,7 +32,7 @@ public class Gt02Protocol extends BaseProtocol {
     public void initTrackerServers(List<TrackerServer> serverList) {
         serverList.add(new TrackerServer(false, getName()) {
             @Override
-            protected void addSpecificHandlers(ChannelPipeline pipeline) {
+            protected void addProtocolHandlers(PipelineBuilder pipeline) {
                 pipeline.addLast("frameDecoder", new LengthFieldBasedFrameDecoder(256, 2, 1, 2, 0));
                 pipeline.addLast("objectDecoder", new Gt02ProtocolDecoder(Gt02Protocol.this));
             }
diff --git a/src/org/traccar/protocol/Gt02ProtocolDecoder.java b/src/org/traccar/protocol/Gt02ProtocolDecoder.java
index 3eb3e193a..d222acaab 100644
--- a/src/org/traccar/protocol/Gt02ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Gt02ProtocolDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012 - 2016 Anton Tananaev (anton@traccar.org)
+ * Copyright 2012 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
diff --git a/src/org/traccar/protocol/Gt06FrameDecoder.java b/src/org/traccar/protocol/Gt06FrameDecoder.java
index c8b5e56ae..41e56415a 100644
--- a/src/org/traccar/protocol/Gt06FrameDecoder.java
+++ b/src/org/traccar/protocol/Gt06FrameDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2014 - 2017 Anton Tananaev (anton@traccar.org)
+ * Copyright 2014 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,16 +15,16 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.buffer.ChannelBuffer;
-import org.jboss.netty.channel.Channel;
-import org.jboss.netty.channel.ChannelHandlerContext;
-import org.jboss.netty.handler.codec.frame.FrameDecoder;
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelHandlerContext;
+import org.traccar.BaseFrameDecoder;
 
-public class Gt06FrameDecoder extends FrameDecoder {
+public class Gt06FrameDecoder extends BaseFrameDecoder {
 
     @Override
     protected Object decode(
-            ChannelHandlerContext ctx, Channel channel, ChannelBuffer buf) throws Exception {
+            ChannelHandlerContext ctx, Channel channel, ByteBuf buf) throws Exception {
 
         if (buf.readableBytes() < 5) {
             return null;
diff --git a/src/org/traccar/protocol/Gt06Protocol.java b/src/org/traccar/protocol/Gt06Protocol.java
index f45ac95ee..e00a585ca 100644
--- a/src/org/traccar/protocol/Gt06Protocol.java
+++ b/src/org/traccar/protocol/Gt06Protocol.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 Anton Tananaev (anton@traccar.org)
+ * Copyright 2015 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,9 +15,8 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.bootstrap.ServerBootstrap;
-import org.jboss.netty.channel.ChannelPipeline;
 import org.traccar.BaseProtocol;
+import org.traccar.PipelineBuilder;
 import org.traccar.TrackerServer;
 import org.traccar.model.Command;
 
@@ -35,9 +34,9 @@ public class Gt06Protocol extends BaseProtocol {
 
     @Override
     public void initTrackerServers(List<TrackerServer> serverList) {
-        serverList.add(new TrackerServer(new ServerBootstrap(), getName()) {
+        serverList.add(new TrackerServer(false, getName()) {
             @Override
-            protected void addSpecificHandlers(ChannelPipeline pipeline) {
+            protected void addProtocolHandlers(PipelineBuilder pipeline) {
                 pipeline.addLast("frameDecoder", new Gt06FrameDecoder());
                 pipeline.addLast("objectEncoder", new Gt06ProtocolEncoder());
                 pipeline.addLast("objectDecoder", new Gt06ProtocolDecoder(Gt06Protocol.this));
diff --git a/src/org/traccar/protocol/Gt06ProtocolDecoder.java b/src/org/traccar/protocol/Gt06ProtocolDecoder.java
index 3e5ebc8c5..44dbf9d8b 100644
--- a/src/org/traccar/protocol/Gt06ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Gt06ProtocolDecoder.java
@@ -15,9 +15,10 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.buffer.ChannelBuffer;
-import org.jboss.netty.buffer.ChannelBuffers;
-import org.jboss.netty.channel.Channel;
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.ByteBufUtil;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.Channel;
 import org.traccar.BaseProtocolDecoder;
 import org.traccar.Context;
 import org.traccar.DeviceSession;
@@ -44,7 +45,7 @@ import java.util.regex.Pattern;
 
 public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
 
-    private final Map<Integer, ChannelBuffer> photos = new HashMap<>();
+    private final Map<Integer, ByteBuf> photos = new HashMap<>();
 
     public Gt06ProtocolDecoder(Gt06Protocol protocol) {
         super(protocol);
@@ -162,9 +163,9 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
         }
     }
 
-    private void sendResponse(Channel channel, boolean extended, int type, int index, ChannelBuffer content) {
+    private void sendResponse(Channel channel, boolean extended, int type, int index, ByteBuf content) {
         if (channel != null) {
-            ChannelBuffer response = ChannelBuffers.dynamicBuffer();
+            ByteBuf response = Unpooled.buffer();
             int length = 5 + (content != null ? content.readableBytes() : 0);
             if (extended) {
                 response.writeShort(0x7979);
@@ -179,22 +180,22 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
             }
             response.writeShort(index);
             response.writeShort(Checksum.crc16(Checksum.CRC16_X25,
-                    response.toByteBuffer(2, response.writerIndex() - 2)));
+                    response.nioBuffer(2, response.writerIndex() - 2)));
             response.writeByte('\r'); response.writeByte('\n'); // ending
             channel.write(response);
         }
     }
 
     private void sendPhotoRequest(Channel channel, int pictureId) {
-        ChannelBuffer photo = photos.get(pictureId);
-        ChannelBuffer content = ChannelBuffers.dynamicBuffer();
+        ByteBuf photo = photos.get(pictureId);
+        ByteBuf content = Unpooled.buffer();
         content.writeInt(pictureId);
         content.writeInt(photo.writerIndex());
         content.writeShort(Math.min(photo.writableBytes(), 1024));
         sendResponse(channel, false, MSG_X1_PHOTO_DATA, 0, content);
     }
 
-    private boolean decodeGps(Position position, ChannelBuffer buf, boolean hasLength, TimeZone timezone) {
+    private boolean decodeGps(Position position, ByteBuf buf, boolean hasLength, TimeZone timezone) {
 
         DateBuilder dateBuilder = new DateBuilder(timezone)
                 .setDate(buf.readUnsignedByte(), buf.readUnsignedByte(), buf.readUnsignedByte())
@@ -232,7 +233,7 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
         return true;
     }
 
-    private boolean decodeLbs(Position position, ChannelBuffer buf, boolean hasLength) {
+    private boolean decodeLbs(Position position, ByteBuf buf, boolean hasLength) {
 
         int length = 0;
         if (hasLength) {
@@ -255,7 +256,7 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
         return true;
     }
 
-    private boolean decodeStatus(Position position, ChannelBuffer buf) {
+    private boolean decodeStatus(Position position, ByteBuf buf) {
 
         int status = buf.readUnsignedByte();
 
@@ -367,7 +368,7 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
         return position;
     }
 
-    private Object decodeBasic(Channel channel, SocketAddress remoteAddress, ChannelBuffer buf) throws Exception {
+    private Object decodeBasic(Channel channel, SocketAddress remoteAddress, ByteBuf buf) throws Exception {
 
         int length = buf.readUnsignedByte();
         int dataLength = length - 5;
@@ -386,7 +387,7 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
 
         if (type == MSG_LOGIN) {
 
-            String imei = ChannelBuffers.hexDump(buf.readBytes(8)).substring(1);
+            String imei = ByteBufUtil.hexDump(buf.readBytes(8)).substring(1);
             buf.readUnsignedShort(); // type
 
             deviceSession = getDeviceSession(channel, remoteAddress, imei);
@@ -435,7 +436,7 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
         } else if (type == MSG_ADDRESS_REQUEST) {
 
             String response = "NA&&NA&&0##";
-            ChannelBuffer content = ChannelBuffers.dynamicBuffer();
+            ByteBuf content = Unpooled.buffer();
             content.writeByte(response.length());
             content.writeInt(0);
             content.writeBytes(response.getBytes(StandardCharsets.US_ASCII));
@@ -444,7 +445,7 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
         } else if (type == MSG_TIME_REQUEST) {
 
             Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
-            ChannelBuffer content = ChannelBuffers.dynamicBuffer();
+            ByteBuf content = Unpooled.buffer();
             content.writeByte(calendar.get(Calendar.YEAR) - 2000);
             content.writeByte(calendar.get(Calendar.MONTH) + 1);
             content.writeByte(calendar.get(Calendar.DAY_OF_MONTH));
@@ -482,7 +483,7 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
             buf.readUnsignedByte(); // photo source
             buf.readUnsignedByte(); // picture format
 
-            ChannelBuffer photo = ChannelBuffers.buffer(buf.readInt());
+            ByteBuf photo = Unpooled.buffer(buf.readInt());
             int pictureId = buf.readInt();
             photos.put(pictureId, photo);
             sendPhotoRequest(channel, pictureId);
@@ -500,7 +501,7 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
         return null;
     }
 
-    private Object decodeWifi(ChannelBuffer buf, DeviceSession deviceSession) throws Exception {
+    private Object decodeWifi(ByteBuf buf, DeviceSession deviceSession) throws Exception {
 
         Position position = new Position(getProtocolName());
         position.setDeviceId(deviceSession.getDeviceId());
@@ -537,7 +538,7 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
         return position;
     }
 
-    private Object decodeBasicOther(Channel channel, ChannelBuffer buf,
+    private Object decodeBasicOther(Channel channel, ByteBuf buf,
             DeviceSession deviceSession, int type, int dataLength) throws Exception {
 
         Position position = new Position(getProtocolName());
@@ -571,7 +572,7 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
             if (type != MSG_LBS_MULTIPLE && type != MSG_LBS_2) {
                 int wifiCount = buf.readUnsignedByte();
                 for (int i = 0; i < wifiCount; i++) {
-                    String mac = ChannelBuffers.hexDump(buf.readBytes(6)).replaceAll("(..)", "$1:");
+                    String mac = ByteBufUtil.hexDump(buf.readBytes(6)).replaceAll("(..)", "$1:");
                     network.addWifiAccessPoint(WifiAccessPoint.from(
                             mac.substring(0, mac.length() - 1), buf.readUnsignedByte()));
                 }
@@ -619,7 +620,9 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
 
         } else {
 
-            buf.skipBytes(dataLength);
+            if (dataLength > 0) {
+                buf.skipBytes(dataLength);
+            }
             if (type != MSG_COMMAND_0 && type != MSG_COMMAND_1 && type != MSG_COMMAND_2) {
                 sendResponse(channel, false, type, buf.getShort(buf.writerIndex() - 6), null);
             }
@@ -640,7 +643,7 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
         return position;
     }
 
-    private Object decodeExtended(Channel channel, SocketAddress remoteAddress, ChannelBuffer buf) throws Exception {
+    private Object decodeExtended(Channel channel, SocketAddress remoteAddress, ByteBuf buf) throws Exception {
 
         DeviceSession deviceSession = getDeviceSession(channel, remoteAddress);
         if (deviceSession == null) {
@@ -704,7 +707,7 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
 
             int pictureId = buf.readInt();
 
-            ChannelBuffer photo = photos.get(pictureId);
+            ByteBuf photo = photos.get(pictureId);
 
             buf.readUnsignedInt(); // offset
             buf.readBytes(photo, buf.readUnsignedShort());
@@ -772,7 +775,7 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
     protected Object decode(
             Channel channel, SocketAddress remoteAddress, Object msg) throws Exception {
 
-        ChannelBuffer buf = (ChannelBuffer) msg;
+        ByteBuf buf = (ByteBuf) msg;
 
         int header = buf.readShort();
 
diff --git a/src/org/traccar/protocol/Gt06ProtocolEncoder.java b/src/org/traccar/protocol/Gt06ProtocolEncoder.java
index daf045f4f..46b4fa5a4 100644
--- a/src/org/traccar/protocol/Gt06ProtocolEncoder.java
+++ b/src/org/traccar/protocol/Gt06ProtocolEncoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 - 2017 Anton Tananaev (anton@traccar.org)
+ * Copyright 2015 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,8 +15,8 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.buffer.ChannelBuffer;
-import org.jboss.netty.buffer.ChannelBuffers;
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
 import org.traccar.BaseProtocolEncoder;
 import org.traccar.Context;
 import org.traccar.helper.Checksum;
@@ -27,11 +27,11 @@ import java.nio.charset.StandardCharsets;
 
 public class Gt06ProtocolEncoder extends BaseProtocolEncoder {
 
-    private ChannelBuffer encodeContent(long deviceId, String content) {
+    private ByteBuf encodeContent(long deviceId, String content) {
 
         boolean language = Context.getIdentityManager().lookupAttributeBoolean(deviceId, "gt06.language", false, true);
 
-        ChannelBuffer buf = ChannelBuffers.dynamicBuffer();
+        ByteBuf buf = Unpooled.buffer();
 
         buf.writeByte(0x78);
         buf.writeByte(0x78);
@@ -50,7 +50,7 @@ public class Gt06ProtocolEncoder extends BaseProtocolEncoder {
 
         buf.writeShort(0); // message index
 
-        buf.writeShort(Checksum.crc16(Checksum.CRC16_X25, buf.toByteBuffer(2, buf.writerIndex() - 2)));
+        buf.writeShort(Checksum.crc16(Checksum.CRC16_X25, buf.nioBuffer(2, buf.writerIndex() - 2)));
 
         buf.writeByte('\r');
         buf.writeByte('\n');
diff --git a/src/org/traccar/protocol/Gt30Protocol.java b/src/org/traccar/protocol/Gt30Protocol.java
index 186002a35..43bb5a70b 100644
--- a/src/org/traccar/protocol/Gt30Protocol.java
+++ b/src/org/traccar/protocol/Gt30Protocol.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Anton Tananaev (anton@traccar.org)
+ * Copyright 2017 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,12 +15,11 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.bootstrap.ServerBootstrap;
-import org.jboss.netty.channel.ChannelPipeline;
-import org.jboss.netty.handler.codec.frame.LineBasedFrameDecoder;
-import org.jboss.netty.handler.codec.string.StringDecoder;
-import org.jboss.netty.handler.codec.string.StringEncoder;
+import io.netty.handler.codec.LineBasedFrameDecoder;
+import io.netty.handler.codec.string.StringDecoder;
+import io.netty.handler.codec.string.StringEncoder;
 import org.traccar.BaseProtocol;
+import org.traccar.PipelineBuilder;
 import org.traccar.TrackerServer;
 
 import java.util.List;
@@ -33,9 +32,9 @@ public class Gt30Protocol extends BaseProtocol {
 
     @Override
     public void initTrackerServers(List<TrackerServer> serverList) {
-        serverList.add(new TrackerServer(new ServerBootstrap(), getName()) {
+        serverList.add(new TrackerServer(false, getName()) {
             @Override
-            protected void addSpecificHandlers(ChannelPipeline pipeline) {
+            protected void addProtocolHandlers(PipelineBuilder pipeline) {
                 pipeline.addLast("frameDecoder", new LineBasedFrameDecoder(1024));
                 pipeline.addLast("stringEncoder", new StringEncoder());
                 pipeline.addLast("stringDecoder", new StringDecoder());
diff --git a/src/org/traccar/protocol/Gt30ProtocolDecoder.java b/src/org/traccar/protocol/Gt30ProtocolDecoder.java
index 27081a108..ac1557994 100644
--- a/src/org/traccar/protocol/Gt30ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Gt30ProtocolDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Anton Tananaev (anton@traccar.org)
+ * Copyright 2017 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,7 +15,7 @@
  */
 package org.traccar.protocol;
 
-import org.jboss.netty.channel.Channel;
+import io.netty.channel.Channel;
 import org.traccar.BaseProtocolDecoder;
 import org.traccar.DeviceSession;
 import org.traccar.helper.DateBuilder;