Refactor NDTPv6 protocol

7 files changed, 316 insertions, 405 deletions

diff --git a/src/main/java/org/traccar/protocol/NDTPv6Protocol.java b/src/main/java/org/traccar/protocol/NDTPv6Protocol.java
deleted file mode 100644
index 78dc11b50..000000000
--- a/src/main/java/org/traccar/protocol/NDTPv6Protocol.java
+++ /dev/null
@@ -1,26 +0,0 @@
-/*

- * 2020 - NDTP v6 Protocol

- */

-package org.traccar.protocol;

-

-import org.traccar.BaseProtocol;

-import org.traccar.PipelineBuilder;

-import org.traccar.TrackerServer;

-import org.traccar.config.Config;

-

-import javax.inject.Inject;

-

-public class NDTPv6Protocol extends BaseProtocol {

-

-    @Inject

-    public NDTPv6Protocol(Config config) {

-        addServer(

-                new TrackerServer(config, getName(), false) {

-                    @Override

-                    protected void addProtocolHandlers(PipelineBuilder pipeline, Config config) {

-                        pipeline.addLast(new NDTPv6ProtocolDecoder(NDTPv6Protocol.this));

-                    }

-                }

-        );

-    }

-}

diff --git a/src/main/java/org/traccar/protocol/NDTPv6ProtocolDecoder.java b/src/main/java/org/traccar/protocol/NDTPv6ProtocolDecoder.java
deleted file mode 100644
index 788afd65b..000000000
--- a/src/main/java/org/traccar/protocol/NDTPv6ProtocolDecoder.java
+++ /dev/null
@@ -1,309 +0,0 @@
-/*

- * 2020 - NDTP v6 Protocol Decoder

- */

-package org.traccar.protocol;

-

-import io.netty.buffer.ByteBuf;

-import io.netty.buffer.Unpooled;

-import io.netty.channel.Channel;

-

-import java.net.SocketAddress;

-import java.nio.ByteBuffer;

-import java.nio.ByteOrder;

-import java.util.Date;

-

-import org.traccar.BaseProtocolDecoder;

-import org.traccar.NetworkMessage;

-import org.traccar.Protocol;

-import org.traccar.helper.BitUtil;

-import org.traccar.helper.Checksum;

-import org.traccar.model.Position;

-import org.traccar.session.DeviceSession;

-

-public class NDTPv6ProtocolDecoder extends BaseProtocolDecoder {

-

-    public NDTPv6ProtocolDecoder(Protocol protocol) {

-        super(protocol);

-    }

-

-    private static final byte[] SIGNATURE = {0x7E, 0x7E};

-

-    private static final int NPL_FLAG_CRC = 2;

-    private static final int NPH_RESULT_OK = 0x00000000;

-    private static final int NPL_TYPE_NPH = 2;

-    private static final int NPL_ADDRESS_SERVER = 0;

-

-    /* common packets for all services */

-    private static final int NPH_RESULT = 0;

-

-    /* NPH service types */

-    private static final int NPH_SRV_GENERIC_CONTROLS = 0;

-    private static final int NPH_SRV_NAVDATA = 1;

-

-    /* NPH_SRV_GENERIC_CONTROLS packets */

-    private static final int NPH_SGC_RESULT = NPH_RESULT;

-    private static final int NPH_SGC_CONN_REQUEST = 100;

-

-    /* NPH_SRV_NAVDATA packets */

-    private static final int NPH_SND_RESULT = NPH_RESULT;

-

-    private static void sendResultResponse(

-            Channel channel,

-            short serviceId,

-            int requestId,

-            int nphSendResult,

-            int nphResult

-    ) {

-        // Формирование пакета данных

-        byte[] serviceIdBytes = ByteBuffer

-                .allocate(2)

-                .order(ByteOrder.LITTLE_ENDIAN)

-                .putShort(serviceId)

-                .array();

-        byte[] nphSendResultBytes = ByteBuffer

-                .allocate(4)

-                .order(ByteOrder.LITTLE_ENDIAN)

-                .putInt(nphSendResult)

-                .array();

-        byte[] requestIdBytes = ByteBuffer

-                .allocate(4)

-                .order(ByteOrder.LITTLE_ENDIAN)

-                .putInt(requestId)

-                .array();

-        byte[] nphResultBytes = ByteBuffer

-                .allocate(4)

-                .order(ByteOrder.LITTLE_ENDIAN)

-                .putInt(nphResult)

-                .array();

-

-        byte[] allByteArray = new byte[serviceIdBytes.length +

-                requestIdBytes.length +

-                nphSendResultBytes.length +

-                nphResultBytes.length];

-

-        System.arraycopy(serviceIdBytes, 0, allByteArray, 0, serviceIdBytes.length);

-        System.arraycopy(

-                nphSendResultBytes,

-                0,

-                allByteArray,

-                serviceIdBytes.length,

-                nphSendResultBytes.length

-        );

-        System.arraycopy(

-                requestIdBytes,

-                0,

-                allByteArray,

-                serviceIdBytes.length + nphSendResultBytes.length,

-                requestIdBytes.length

-        );

-        System.arraycopy(

-                nphResultBytes,

-                0,

-                allByteArray,

-                serviceIdBytes.length + requestIdBytes.length + nphSendResultBytes.length,

-                nphResultBytes.length

-        );

-

-        // ПАКЕТ ОТВЕТА КЛИЕНТУ

-        ByteBuf response = Unpooled.buffer();

-        // NPL

-        response.writeBytes(SIGNATURE);

-        response.writeShortLE(allByteArray.length); // Размер данных

-        response.writeShortLE(NPL_FLAG_CRC); // Флаги

-

-        response.writeShort(

-                Checksum.crc16(Checksum.CRC16_MODBUS, ByteBuffer.wrap(allByteArray))

-        ); // CRC

-        response.writeByte(NPL_TYPE_NPH); // Тип

-        response.writeIntLE(NPL_ADDRESS_SERVER); // peer_address

-        response.writeShortLE(0); // request_id

-

-        response.writeBytes(allByteArray);

-

-        channel.writeAndFlush(

-                new NetworkMessage(response, channel.remoteAddress())

-        );

-    }

-

-    private static final short MAIN_NAV_DATA = 0;

-    private static final short ADDITIONAL_NAV_DATA = 2;

-

-    private void decodeData(ByteBuf buf, Position position, int dataType) {

-        if (dataType == NPH_SRV_NAVDATA) {

-            short cellType;

-            short cellNumber;

-

-            cellType = buf.readUnsignedByte(); // Тип ячейки

-            cellNumber = buf.readUnsignedByte(); // Номер ячейки

-            if (cellType == MAIN_NAV_DATA && (cellNumber == 0 || cellNumber == 1)) {

-                position.setTime(new Date(buf.readUnsignedIntLE() * 1000)); // Значение реального времени unix

-                position.setLongitude(buf.readIntLE() / 10000000.0); // Долгота в градусах, умноженная на 10 000 000

-                position.setLatitude(buf.readIntLE() / 10000000.0); // Широта в градусах, умноженная на 10 000 000

-

-                short flags = buf.readUnsignedByte(); // Достоверность навигационных данных:

-                // bit7 - достоверность нав. данных (1 - достоверны, 0 – нет);

-                // bit6 - полушарие долготы (1 – E, 0 – W);

-                // bit5 - полушарие широты (1 – N, 0 – S);

-                // bit4 - флаг работы от встроенного аккумулятора;

-                // bit3 – флаг первоначального включения;

-                // bit2 – состояние SOS (1 – SOS, 0 – нет SOS);

-                // bit1 – флаг тревожной информации (один из параметров

-                // находится в диапазоне тревоги)

-                position.setValid(BitUtil.check(flags, 7));

-                if (BitUtil.check(flags, 1)) {

-                    position.set(Position.KEY_ALARM, Position.ALARM_GENERAL);

-                }

-                position.set(Position.KEY_BATTERY, buf.readUnsignedByte() * 20); // Напряжение батареи, 1бит = 20мВ

-                position.set(Position.KEY_OBD_SPEED, buf.readUnsignedShortLE()); // Средняя скорость за период в км/ч

-                position.setSpeed(buf.readUnsignedShortLE() / 1.85); // Максимальная скорость за период в км/ч

-

-                int course = buf.readUnsignedShortLE(); // Направление движения

-                position.setCourse(course);

-

-                position.set(Position.KEY_DISTANCE, buf.readUnsignedShortLE()); // Пройденный путь, м

-                position.setAltitude(buf.readShortLE()); // Высота над уровнем моря в метрах (-18000 - +18000)

-                position.set(Position.KEY_SATELLITES, buf.readUnsignedByte()); // Количество видимых спутников

-                position.set(Position.KEY_PDOP, buf.readUnsignedByte()); // PDOP

-            }

-            cellType = buf.readUnsignedByte(); // Тип ячейки

-            cellNumber = buf.readUnsignedByte(); // Номер ячейки

-            if (cellType == ADDITIONAL_NAV_DATA && cellNumber == 0) {

-                int analogIn1 = buf.readUnsignedShortLE(); // Значение 0 аналогового входа в 16 битном формате

-                //(analogIn1 - отражает напряжение на батерии для радиоборта)

-                int analogIn2 = buf.readUnsignedShortLE(); // Значение 1 аналогового входа в 16 битном формате

-                int analogIn3 = buf.readUnsignedShortLE(); // Значение 2 аналогового входа в 16 битном формате

-                int analogIn4 = buf.readUnsignedShortLE(); // Значение 3 аналогового входа в 16 битном формате

-

-                buf.readUnsignedByte(); // Значение цифровых входов

-                buf.readUnsignedByte(); // Состояние дискретных выходов

-                buf.readUnsignedShortLE(); // Количество импульсов на дискретном входе 0 с предыдущей нав. отметки

-                buf.readUnsignedShortLE(); // Количество импульсов на дискретном входе 1 с предыдущей нав. отметки

-                buf.readUnsignedShortLE(); // Количество импульсов на дискретном входе 2 с предыдущей нав. отметки

-                buf.readUnsignedShortLE(); // Количество импульсов на дискретном входе 3 с предыдущей нав. отметки

-                buf.readUnsignedIntLE(); // Длина трека с момента первого включения

-

-                position.set(Position.KEY_ANTENNA, buf.readUnsignedByte()); // Сила GSM сигнала

-                position.set(Position.KEY_GPS, buf.readUnsignedByte()); // Состояние GPRS подключения

-                position.set(Position.KEY_ACCELERATION, buf.readUnsignedByte()); // Акселерометр - энергия

-                position.set(Position.KEY_POWER, buf.readUnsignedByte() * 200); // Напряжение борт. сети (1бит - 200мв)

-

-                position.set(Position.PREFIX_ADC + 1, analogIn1 * 1);

-                position.set(Position.PREFIX_ADC + 2, analogIn2 * 1);

-                position.set(Position.PREFIX_ADC + 3, analogIn3 * 1);

-                position.set(Position.PREFIX_ADC + 4, analogIn4 * 1);

-

-                // Расчет уровня батареи

-                // float Voltage = 5 / 4096 * analogIn1; // Вольтаж

-

-                float batteryLevel = (analogIn1 - 3600) / 6;

-

-                if (batteryLevel > 100) {

-                    batteryLevel = 100;

-                }

-                if (batteryLevel < 0) {

-                    batteryLevel = 0;

-                }

-

-                position.set(Position.KEY_BATTERY_LEVEL, batteryLevel);

-            }

-        }

-    }

-

-    @Override

-    protected Object decode(

-            Channel channel,

-            SocketAddress remoteAddress,

-            Object msg

-    )

-            throws Exception {

-        ByteBuf buf = (ByteBuf) msg;

-

-        DeviceSession deviceSession = getDeviceSession(channel, remoteAddress);

-

-        // Заголовок NPL

-        buf.skipBytes(2); // Сигнатура (7e 7e)

-        buf.readUnsignedShortLE(); // Размер данных (nph + размер массива данных)

-        buf.readUnsignedShortLE(); // Флаги соединения (2 - проверять crc)

-        buf.readUnsignedShortLE(); // CRC (Modbus)

-        buf.readUnsignedByte(); // Тип пакета (nph)

-        buf.readUnsignedIntLE(); // Адрес участника соединения

-        buf.readUnsignedShortLE(); // Идентификатор NPL

-

-        // Заголовок NPH

-        int serviceId = buf.readUnsignedShortLE(); // Идентификатор услуги (NPH_SRV_NAVDATA) service_id

-        int serviceType = buf.readUnsignedShortLE(); // Тип пакета

-        buf.readUnsignedShortLE(); // Флаг (1 - требуется подтверждение) NPH_FLAG_REQUEST

-        long requestId = buf.readUnsignedIntLE(); // Идентификатор nph

-

-        if (

-                deviceSession == null &&

-                        serviceId == NPH_SRV_GENERIC_CONTROLS &&

-                        serviceType == NPH_SGC_CONN_REQUEST

-        ) { // Регистрация устройства

-            buf.readUnsignedShortLE(); // Версия протокола NDTP (старший номер)

-            buf.readUnsignedShortLE(); // Версия протокола NDTP (младший номер)

-            buf.readUnsignedShortLE(); // Опции соединения (connection_flags)

-            // Определяет настройки соединения,

-            // которые будут использоваться после установки соединения.

-            // На данный момент их две:

-            //  - бит0: шифровать пакеты (0 - нет, 1 — да)

-            //  - бит1: рассчитывать CRC пакетов (0 - нет, 1 — да)

-            //  - бит2: подключение симулятора (0 — подключается обычный клиент,

-            //                                  1 подключается симулятор)

-            //  - бит3:  тип алгоритма шифрования.

-            //  -            0 - blowfish

-            //  -            1 – ГОСТ

-            //  - бит8: наличие поля IMEI (0 - нет, 1 — да)

-            //  - бит9: наличие поля IMSI (0 - нет, 1 — да)

-            //  - остальные биты не используются.

-            int deviceId = buf.readUnsignedShortLE();

-            Position position = new Position(getProtocolName());

-            deviceSession =

-                    getDeviceSession(channel, remoteAddress, String.valueOf(deviceId));

-            position.setDeviceId(deviceSession.getDeviceId());

-

-            if (channel != null) {

-                sendResultResponse(

-                        channel,

-                        (short) serviceId,

-                        (int) requestId,

-                        NPH_SND_RESULT,

-                        NPH_RESULT_OK

-                );

-            }

-

-            position.set(Position.KEY_RESULT, String.valueOf(NPH_SGC_RESULT));

-            position.setTime(new Date());

-            getLastLocation(position, new Date());

-            position.setValid(false);

-

-            return position;

-        }

-

-        if (serviceId == NPH_SRV_NAVDATA) {

-            deviceSession = getDeviceSession(channel, remoteAddress);

-            if (deviceSession == null) {

-                return null;

-            }

-

-            Position position = new Position(getProtocolName());

-            position.setDeviceId(deviceSession.getDeviceId());

-

-            if (channel != null) {

-                sendResultResponse(

-                        channel,

-                        (short) serviceId,

-                        (int) requestId,

-                        NPH_SND_RESULT,

-                        NPH_RESULT_OK

-                );

-            }

-

-            decodeData(buf, position, NPH_SRV_NAVDATA);

-

-            return position;

-        }

-

-        return null;

-    }

-}

diff --git a/src/main/java/org/traccar/protocol/NDTPv6ProtocolEncoder.java b/src/main/java/org/traccar/protocol/NDTPv6ProtocolEncoder.java
deleted file mode 100644
index af0dd58f9..000000000
--- a/src/main/java/org/traccar/protocol/NDTPv6ProtocolEncoder.java
+++ /dev/null
@@ -1,38 +0,0 @@
-/*
- * 2020 - NDTP v6 Protocol Encoder
- */
-package org.traccar.protocol;
-
-import io.netty.buffer.ByteBuf;
-import io.netty.buffer.Unpooled;
-import java.nio.charset.StandardCharsets;
-import org.traccar.BaseProtocolEncoder;
-import org.traccar.Protocol;
-import org.traccar.model.Command;
-
-public class NDTPv6ProtocolEncoder extends BaseProtocolEncoder {
-
-  public NDTPv6ProtocolEncoder(Protocol protocol) {
-    super(protocol);
-  }
-
-  private ByteBuf encodeCommand(String commandString) {
-    ByteBuf buffer = Unpooled.buffer();
-    buffer.writeBytes(commandString.getBytes(StandardCharsets.US_ASCII));
-    return buffer;
-  }
-
-  @Override
-  protected Object encodeCommand(Command command) {
-    switch (command.getType()) {
-      case Command.TYPE_IDENTIFICATION:
-        return encodeCommand("BB+IDNT");
-      case Command.TYPE_REBOOT_DEVICE:
-        return encodeCommand("BB+RESET");
-      case Command.TYPE_POSITION_SINGLE:
-        return encodeCommand("BB+RRCD");
-      default:
-        return null;
-    }
-  }
-}
diff --git a/src/main/java/org/traccar/protocol/NDTPv6FrameDecoder.java b/src/main/java/org/traccar/protocol/NdtpV6FrameDecoder.java
index c869b11a4..5b610013a 100644
--- a/src/main/java/org/traccar/protocol/NDTPv6FrameDecoder.java
+++ b/src/main/java/org/traccar/protocol/NdtpV6FrameDecoder.java
@@ -1,32 +1,32 @@
-/*

- * 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.

- * You may obtain a copy of the License at

- *

- *     http://www.apache.org/licenses/LICENSE-2.0

- *

- * Unless required by applicable law or agreed to in writing, software

- * distributed under the License is distributed on an "AS IS" BASIS,

- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

- * See the License for the specific language governing permissions and

- * limitations under the License.

- */

-package org.traccar.protocol;

-

-import io.netty.buffer.ByteBuf;

-import io.netty.channel.Channel;

-import io.netty.channel.ChannelHandlerContext;

-import org.traccar.BaseFrameDecoder;

-

-public class NDTPv6FrameDecoder extends BaseFrameDecoder {

-

-    @Override

-    protected Object decode(

-            ChannelHandlerContext ctx, Channel channel, ByteBuf buf) throws Exception {

-

-        return buf;

-    }

-

-}

+/*
+ * Copyright 2022 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.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.traccar.protocol;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelHandlerContext;
+import org.traccar.BaseFrameDecoder;
+
+public class NdtpV6FrameDecoder extends BaseFrameDecoder {
+
+    @Override
+    protected Object decode(
+            ChannelHandlerContext ctx, Channel channel, ByteBuf buf) throws Exception {
+
+        return buf;
+    }
+
+}
diff --git a/src/main/java/org/traccar/protocol/NdtpV6Protocol.java b/src/main/java/org/traccar/protocol/NdtpV6Protocol.java
new file mode 100644
index 000000000..ce0dbbef2
--- /dev/null
+++ b/src/main/java/org/traccar/protocol/NdtpV6Protocol.java
@@ -0,0 +1,39 @@
+/*
+ * Copyright 2022 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.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.traccar.protocol;
+
+import io.netty.handler.codec.string.StringEncoder;
+import org.traccar.BaseProtocol;
+import org.traccar.PipelineBuilder;
+import org.traccar.TrackerServer;
+import org.traccar.config.Config;
+
+import javax.inject.Inject;
+
+public class NdtpV6Protocol extends BaseProtocol {
+
+    @Inject
+    public NdtpV6Protocol(Config config) {
+        addServer(new TrackerServer(config, getName(), false) {
+            @Override
+            protected void addProtocolHandlers(PipelineBuilder pipeline, Config config) {
+                pipeline.addLast(new StringEncoder());
+                pipeline.addLast(new NdtpV6ProtocolDecoder(NdtpV6Protocol.this));
+            }
+        });
+    }
+
+}
diff --git a/src/main/java/org/traccar/protocol/NdtpV6ProtocolDecoder.java b/src/main/java/org/traccar/protocol/NdtpV6ProtocolDecoder.java
new file mode 100644
index 000000000..35cb0bae8
--- /dev/null
+++ b/src/main/java/org/traccar/protocol/NdtpV6ProtocolDecoder.java
@@ -0,0 +1,203 @@
+/*
+ * Copyright 2022 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.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.traccar.protocol;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.Channel;
+import org.traccar.BaseProtocolDecoder;
+import org.traccar.NetworkMessage;
+import org.traccar.Protocol;
+import org.traccar.helper.BitUtil;
+import org.traccar.helper.Checksum;
+import org.traccar.helper.UnitsConverter;
+import org.traccar.model.Position;
+import org.traccar.session.DeviceSession;
+
+import java.net.SocketAddress;
+import java.util.Date;
+
+public class NdtpV6ProtocolDecoder extends BaseProtocolDecoder {
+
+    public NdtpV6ProtocolDecoder(Protocol protocol) {
+        super(protocol);
+    }
+
+    private static final byte[] SIGNATURE = {0x7E, 0x7E};
+
+    private static final int NPL_FLAG_CRC = 2;
+    private static final int NPH_RESULT_OK = 0x00000000;
+    private static final int NPL_TYPE_NPH = 2;
+    private static final int NPL_ADDRESS_SERVER = 0;
+
+    private static final int NPH_RESULT = 0;
+
+    private static final int NPH_SRV_GENERIC_CONTROLS = 0;
+    private static final int NPH_SRV_NAVDATA = 1;
+
+    private static final int NPH_SGC_RESULT = NPH_RESULT;
+    private static final int NPH_SGC_CONN_REQUEST = 100;
+
+    private static final int NPH_SND_RESULT = NPH_RESULT;
+
+    private void sendResponse(
+            Channel channel, int serviceId, long requestId) {
+
+        ByteBuf content = Unpooled.buffer();
+        content.writeShortLE(serviceId);
+        content.writeIntLE(NPH_SND_RESULT);
+        content.writeIntLE((int) requestId);
+        content.writeIntLE(NPH_RESULT_OK);
+
+        ByteBuf response = Unpooled.buffer();
+        response.writeBytes(SIGNATURE);
+        response.writeShortLE(content.readableBytes());
+        response.writeShortLE(NPL_FLAG_CRC); // flags
+        response.writeShort(Checksum.crc16(Checksum.CRC16_MODBUS, content.nioBuffer()));
+        response.writeByte(NPL_TYPE_NPH); // type
+        response.writeIntLE(NPL_ADDRESS_SERVER); // peer address
+        response.writeShortLE(0); // request id
+        response.writeBytes(content);
+        content.release();
+
+        channel.writeAndFlush(new NetworkMessage(response, channel.remoteAddress()));
+    }
+
+    private static final short MAIN_NAV_DATA = 0;
+    private static final short ADDITIONAL_NAV_DATA = 2;
+
+    private void decodeData(ByteBuf buf, Position position) {
+
+        short itemType;
+        short itemIndex;
+
+        itemType = buf.readUnsignedByte();
+        itemIndex = buf.readUnsignedByte();
+        if (itemType == MAIN_NAV_DATA && (itemIndex == 0 || itemIndex == 1)) {
+
+            position.setTime(new Date(buf.readUnsignedIntLE() * 1000));
+            position.setLongitude(buf.readIntLE() / 10000000.0);
+            position.setLatitude(buf.readIntLE() / 10000000.0);
+
+            short flags = buf.readUnsignedByte();
+            position.setValid(BitUtil.check(flags, 7));
+            if (BitUtil.check(flags, 1)) {
+                position.set(Position.KEY_ALARM, Position.ALARM_GENERAL);
+            }
+
+            position.set(Position.KEY_BATTERY, buf.readUnsignedByte() * 20);
+            position.set(Position.KEY_OBD_SPEED, buf.readUnsignedShortLE());
+            position.setSpeed(UnitsConverter.knotsFromKph(buf.readUnsignedShortLE()));
+            position.setCourse(buf.readUnsignedShortLE());
+
+            position.set(Position.KEY_ODOMETER, buf.readUnsignedShortLE());
+            position.setAltitude(buf.readShortLE());
+            position.set(Position.KEY_SATELLITES, buf.readUnsignedByte());
+            position.set(Position.KEY_PDOP, buf.readUnsignedByte());
+        }
+
+        itemType = buf.readUnsignedByte();
+        itemIndex = buf.readUnsignedByte();
+        if (itemType == ADDITIONAL_NAV_DATA && itemIndex == 0) {
+
+            position.set(Position.KEY_BATTERY_LEVEL, Math.max((buf.readUnsignedShortLE() - 3600) / 6, 100));
+            position.set(Position.PREFIX_ADC + 2, buf.readUnsignedShortLE());
+            position.set(Position.PREFIX_ADC + 3, buf.readUnsignedShortLE());
+            position.set(Position.PREFIX_ADC + 4, buf.readUnsignedShortLE());
+
+            buf.readUnsignedByte(); // inputs
+            buf.readUnsignedByte(); // outputs
+            buf.readUnsignedShortLE(); // in1 count
+            buf.readUnsignedShortLE(); // in2 count
+            buf.readUnsignedShortLE(); // in3 count
+            buf.readUnsignedShortLE(); // in4 count
+            buf.readUnsignedIntLE(); // track length
+
+            position.set(Position.KEY_ANTENNA, buf.readUnsignedByte());
+            position.set(Position.KEY_GPS, buf.readUnsignedByte());
+            position.set(Position.KEY_ACCELERATION, buf.readUnsignedByte());
+            position.set(Position.KEY_POWER, buf.readUnsignedByte() * 200);
+        }
+    }
+
+    @Override
+    protected Object decode(
+            Channel channel, SocketAddress remoteAddress, Object msg) throws Exception {
+
+        ByteBuf buf = (ByteBuf) msg;
+
+        DeviceSession deviceSession = getDeviceSession(channel, remoteAddress);
+
+        buf.skipBytes(2); // signature
+        buf.readUnsignedShortLE(); // length
+        buf.readUnsignedShortLE(); // connection flags
+        buf.readUnsignedShortLE(); // checksum
+        buf.readUnsignedByte(); // type
+        buf.readUnsignedIntLE(); // address
+        buf.readUnsignedShortLE(); // identification
+
+        int serviceId = buf.readUnsignedShortLE();
+        int serviceType = buf.readUnsignedShortLE();
+        buf.readUnsignedShortLE(); // request flags
+        long requestId = buf.readUnsignedIntLE();
+
+        if (deviceSession == null && serviceId == NPH_SRV_GENERIC_CONTROLS && serviceType == NPH_SGC_CONN_REQUEST) {
+
+            buf.readUnsignedShortLE(); // version major
+            buf.readUnsignedShortLE(); // version minor
+            buf.readUnsignedShortLE(); // connection flags
+
+            int deviceId = buf.readUnsignedShortLE();
+            Position position = new Position(getProtocolName());
+            deviceSession = getDeviceSession(channel, remoteAddress, String.valueOf(deviceId));
+            position.setDeviceId(deviceSession.getDeviceId());
+
+            if (channel != null) {
+                sendResponse(channel, serviceId, requestId);
+            }
+
+            position.set(Position.KEY_RESULT, String.valueOf(NPH_SGC_RESULT));
+            position.setTime(new Date());
+            getLastLocation(position, new Date());
+            position.setValid(false);
+
+            return position;
+
+        }
+
+        if (serviceId == NPH_SRV_NAVDATA) {
+
+            deviceSession = getDeviceSession(channel, remoteAddress);
+            if (deviceSession == null) {
+                return null;
+            }
+
+            Position position = new Position(getProtocolName());
+            position.setDeviceId(deviceSession.getDeviceId());
+
+            if (channel != null) {
+                sendResponse(channel, serviceId, requestId);
+            }
+
+            decodeData(buf, position);
+
+            return position;
+        }
+
+        return null;
+    }
+
+}
diff --git a/src/main/java/org/traccar/protocol/NdtpV6ProtocolEncoder.java b/src/main/java/org/traccar/protocol/NdtpV6ProtocolEncoder.java
new file mode 100644
index 000000000..7aac8658a
--- /dev/null
+++ b/src/main/java/org/traccar/protocol/NdtpV6ProtocolEncoder.java
@@ -0,0 +1,42 @@
+/*
+ * Copyright 2022 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.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.traccar.protocol;
+
+import org.traccar.BaseProtocolEncoder;
+import org.traccar.Protocol;
+import org.traccar.model.Command;
+
+public class NdtpV6ProtocolEncoder extends BaseProtocolEncoder {
+
+    public NdtpV6ProtocolEncoder(Protocol protocol) {
+        super(protocol);
+    }
+
+    @Override
+    protected Object encodeCommand(Command command) {
+        switch (command.getType()) {
+            case Command.TYPE_IDENTIFICATION:
+                return "BB+IDNT";
+            case Command.TYPE_REBOOT_DEVICE:
+                return "BB+RESET";
+            case Command.TYPE_POSITION_SINGLE:
+                return "BB+RRCD";
+            default:
+                return null;
+        }
+    }
+
+}