diff --git a/build.gradle b/build.gradle
index 643f0d3b814b1321e9cb38b22fd72dd51d7d1510..6f925af1987f8c0b502b39b0f8809bf8d6692f35 100644
--- a/build.gradle
+++ b/build.gradle
@@ -9,7 +9,7 @@ plugins {
 
 group 'org.bdware.doip'
 
-version '1.5.5'
+version '1.5.6'
 sourceCompatibility = JavaVersion.VERSION_1_8
 targetCompatibility = JavaVersion.VERSION_1_8
 repositories {
diff --git a/src/main/codec/org/bdware/doip/codec/v3/DOIPV3Codec.java b/src/main/codec/org/bdware/doip/codec/v3/DOIPV3Codec.java
index 785ad0b960ad5453921fd15d1e4cb27c39536e20..d1716cf1080243ef18c15d446b2add0e0acb44ad 100644
--- a/src/main/codec/org/bdware/doip/codec/v3/DOIPV3Codec.java
+++ b/src/main/codec/org/bdware/doip/codec/v3/DOIPV3Codec.java
@@ -15,7 +15,7 @@ public class DOIPV3Codec extends ByteToMessageCodec<DOIPV3Message> {
 
     @Override
     protected void encode(ChannelHandlerContext ctx, DOIPV3Message msg, ByteBuf out) throws Exception {
-        LOGGER.info("[DOIPV3Codec Send] " + msg.prettyPrint() + " from:" + ctx.channel().remoteAddress().toString());
+        LOGGER.info("[DOIPV3Codec Send] " + msg.prettyPrint() + " to:" + ctx.channel().remoteAddress().toString());
         msg.writeTo(out);
     }
     @Override
diff --git a/src/main/codec/org/bdware/doip/codec/v3/ExtensionPartFactory.java b/src/main/codec/org/bdware/doip/codec/v3/ExtensionPartFactory.java
index dc40a89521dd96e942f76fa9cfddf3e011ff6b15..87fe4b83efeb2acd9134941024325282d5561fea 100644
--- a/src/main/codec/org/bdware/doip/codec/v3/ExtensionPartFactory.java
+++ b/src/main/codec/org/bdware/doip/codec/v3/ExtensionPartFactory.java
@@ -15,6 +15,8 @@ public class ExtensionPartFactory {
                 return new VDNHeader(bf);
             case ExceptionHead:
                 return new ExceptionHead(bf);
+            case TOKENHeader:
+                return new TOKENHeader(bf);
             default:
                 return null;
         }
diff --git a/src/main/codec/org/bdware/doip/codec/v3/headers/DOLHeader.java b/src/main/codec/org/bdware/doip/codec/v3/headers/DOLHeader.java
index 43ab592c2cc97f9d6dada6f3336c0852821a6e0f..e42ae851b3fe195cb4e7a8224ec54fd8e3da3e31 100644
--- a/src/main/codec/org/bdware/doip/codec/v3/headers/DOLHeader.java
+++ b/src/main/codec/org/bdware/doip/codec/v3/headers/DOLHeader.java
@@ -33,6 +33,10 @@ public class DOLHeader extends ExtensionPart {
         }
     }
 
+    public byte[] getDol() {
+        return dol;
+    }
+
     @Override
     public void writeTo(ByteBuf bf) {
         //keep the correctness of nextType
@@ -46,7 +50,7 @@ public class DOLHeader extends ExtensionPart {
 
     @Override
     public int length() {
-        return 1 + 4 + ((dol == null) ? 0 : dol.length);
+        return 4 + 4 + ((dol == null) ? 0 : dol.length);
     }
 
     @Override
diff --git a/src/main/codec/org/bdware/doip/codec/v3/headers/ExtensionType.java b/src/main/codec/org/bdware/doip/codec/v3/headers/ExtensionType.java
index 88ed9f090c43d071f938865802063044093c6b4d..a2a29c4f206fe3a8fc91e3ef251f871b7cc7fec3 100644
--- a/src/main/codec/org/bdware/doip/codec/v3/headers/ExtensionType.java
+++ b/src/main/codec/org/bdware/doip/codec/v3/headers/ExtensionType.java
@@ -1,7 +1,8 @@
 package org.bdware.doip.codec.v3.headers;
 
 public enum ExtensionType {
-    DOLHeader(0), ENVELOPE(1), VDNHeader(2), ExceptionHead(3), UNKNOWN((-1));
+    DOLHeader(0), ENVELOPE(1), VDNHeader(2), ExceptionHead(3), UNKNOWN(-1),
+    TOKENHeader(4);
     public final int value;
 
     ExtensionType(int i) {
@@ -18,6 +19,8 @@ public enum ExtensionType {
                 return VDNHeader;
             case 3:
                 return ExceptionHead;
+            case 4:
+                return TOKENHeader;
             default:
                 return UNKNOWN;
         }
diff --git a/src/main/codec/org/bdware/doip/codec/v3/headers/TOKENHeader.java b/src/main/codec/org/bdware/doip/codec/v3/headers/TOKENHeader.java
new file mode 100644
index 0000000000000000000000000000000000000000..ed9503b1baeb897294b5ac4c326021304474c0ed
--- /dev/null
+++ b/src/main/codec/org/bdware/doip/codec/v3/headers/TOKENHeader.java
@@ -0,0 +1,50 @@
+package org.bdware.doip.codec.v3.headers;
+
+import io.netty.buffer.ByteBuf;
+
+public class TOKENHeader extends ExtensionPart {
+    public int nextHeader;
+    public int tokenLength;
+    public byte[] token; //string to byte[]
+    public TOKENHeader(ByteBuf bf) {
+        super();
+        nextHeader = bf.readInt();
+        nextType = ExtensionType.fromInt(nextHeader);
+        tokenLength = bf.readInt();
+        if (tokenLength > 0) {
+            token = new byte[tokenLength];
+            bf.readBytes(token);
+        }
+    }
+
+    public TOKENHeader() {
+    }
+
+    @Override
+    public void writeTo(ByteBuf bf) {
+        //keep the correctness of nextType
+        nextHeader = nextType.value;
+        bf.writeInt(nextHeader);
+        if (token != null && token.length > 0) {
+            bf.writeInt(token.length);
+            bf.writeBytes(token);
+        } else bf.writeInt(0);
+    }
+
+    @Override
+    public int length() {
+        return 4 + 4 + ((token == null) ? 0 : token.length);
+    }
+
+
+    @Override
+    public ExtensionType getType() {
+        return ExtensionType.TOKENHeader;
+    }
+
+    @Override
+    public String prettyPrint() {
+        return getType().name() + " token:" + token;
+    }
+
+}
diff --git a/src/main/codec/org/bdware/doip/codec/v3/operations/BasicOperationsV3.java b/src/main/codec/org/bdware/doip/codec/v3/operations/BasicOperationsV3.java
new file mode 100644
index 0000000000000000000000000000000000000000..4e467ee9b2f765c998985bd4bdf5314825d7caa7
--- /dev/null
+++ b/src/main/codec/org/bdware/doip/codec/v3/operations/BasicOperationsV3.java
@@ -0,0 +1,33 @@
+package org.bdware.doip.codec.v3.operations;
+public enum BasicOperationsV3 {
+    CreateVPN("0.DOIP/Op.CreateVPN"), //todo: VPN->VDN
+    RetrieveVPN("0.DOIP/Op.UpdateVPN"),
+    InitVDN("0.DOIP/Op.InitVDN"),
+    UpdateVDN("0.DOIP/Op.UpdateVDN"),
+    AddGWToVDN("0.DOIP/Op.AddGWToVDN"),
+    DeleteGWFromVDN("0.DOIP/Op.DeleteGWFromVDN"),
+    DeleteVDN("0.DOIP/Op.DeleteVDN"),
+    InquireVDN("0.DOIP/Op.InquireVDN"),
+    SearchVDN("0.DOIP/Op.InitVDN"),
+    Unknown("0.DOIP/Op.Unknown");
+
+    private final String name;
+
+    BasicOperationsV3(String displayName) {
+        this.name = displayName;
+    }
+
+    public static BasicOperationsV3 getDoOp(String opStr) {
+        for (BasicOperationsV3 op : BasicOperationsV3.values()) {
+            if (op.getName().equals(opStr)) {
+                return op;
+            }
+        }
+        return Unknown;
+    }
+
+    public String getName() {
+        return name;
+    }
+}
+