diff --git a/src/cas/generic/casClient.cc b/src/cas/generic/casClient.cc
index 8c91702b2..ea9266e31 100644
--- a/src/cas/generic/casClient.cc
+++ b/src/cas/generic/casClient.cc
@@ -113,7 +113,7 @@ void casClient::loadProtoJumpTable()
 	// (use of & here is more portable)
 	//
 	casClient::msgHandlers[CA_PROTO_VERSION] = 
-			&casClient::noopAction;
+			&casClient::versionAction;
 	casClient::msgHandlers[CA_PROTO_EVENT_ADD] = 
 			&casClient::eventAddAction;
 	casClient::msgHandlers[CA_PROTO_EVENT_CANCEL] = 
@@ -388,9 +388,9 @@ caStatus casClient::echoAction ()
 }
 
 /*
- * casClient::noopAction()
+ * casClient::versionAction()
  */
-caStatus casClient::noopAction ()
+caStatus casClient::versionAction ()
 {
 	return S_cas_success;
 }
diff --git a/src/cas/generic/casDGClient.cc b/src/cas/generic/casDGClient.cc
index 1432712b6..d4caf37e6 100644
--- a/src/cas/generic/casDGClient.cc
+++ b/src/cas/generic/casDGClient.cc
@@ -45,8 +45,9 @@
 //
 // casDGClient::casDGClient()
 //
-casDGClient::casDGClient (caServerI &serverIn) :
-	casClient (serverIn, MAX_UDP_RECV+sizeof(cadg))
+casDGClient::casDGClient ( caServerI & serverIn ) :
+	casClient ( serverIn, MAX_UDP_RECV + sizeof ( cadg ) ),
+    seqNoOfReq ( 0 )
 {
 }
 
@@ -331,6 +332,25 @@ caStatus casDGClient::searchFailResponse ( const caHdrLargeArray * mp )
 	return S_cas_success;
 }
 
+/*
+ * casDGClient::versionAction()
+ */
+caStatus casDGClient::versionAction ()
+{
+	const caHdrLargeArray * mp = this->ctx.getMsg();
+
+    if ( mp->m_count != 0 ) {
+        this->minor_version_number = mp->m_count;
+        if ( CA_V411 ( mp->m_count ) ) {
+            this->seqNoOfReq = mp->m_cid;
+        }
+        else {
+            this->seqNoOfReq = 0;
+        }
+    }
+	return S_cas_success;
+}
+
 //
 // casDGClient::sendBeacon()
 // (implemented here because this has knowledge of the protocol)
@@ -379,10 +399,23 @@ outBufClient::flushCondition casDGClient::xSend ( char *pBufIn, // X aCC 361
         assert ( totalBytes+pHdr->cadg_nBytes <= nBytesAvailableToSend );
 
         if ( pHdr->cadg_addr.isValid() ) {
-	        stat = this->osdSend ( reinterpret_cast<char *>(pHdr+1), 
-                pHdr->cadg_nBytes-sizeof(*pHdr), pHdr->cadg_addr );	
+
+            char * pDG = reinterpret_cast < char * > ( pHdr + 1 );
+            unsigned sizeDG = pHdr->cadg_nBytes - sizeof ( *pHdr );
+            caHdr * pMsg = reinterpret_cast < caHdr * > ( pDG );
+            assert ( ntohs ( pMsg->m_cmmd ) == CA_PROTO_VERSION );
+            if ( CA_V411 ( this->minor_version_number ) ) {
+                pMsg->m_cid = htonl ( this->seqNoOfReq );
+                pMsg->m_dataType = htons ( sequenceNoIsValid );
+            }
+            else {
+                pDG += sizeof (caHdr);
+                sizeDG -= sizeof (caHdr);
+            }
+
+	        stat = this->osdSend ( pDG, sizeDG, pHdr->cadg_addr );	
 	        if ( stat != outBufClient::flushProgress ) {
-                 break;
+                break;
             }
         }
 
@@ -510,6 +543,9 @@ caStatus casDGClient::processDG ()
             status = S_cas_sendBlocked;
             break;
         }
+
+        // insert version header at the start of the reply message
+        this->sendVersion ();
         
         cadg *pRespHdr = reinterpret_cast <cadg *> (pRaw);
         
@@ -528,6 +564,8 @@ caStatus casDGClient::processDG ()
         }
 
         this->lastRecvAddr = pReqHdr->cadg_addr;
+        this->seqNoOfReq = 0;
+        this->minor_version_number = 0;
 
         status = this->processMsg ();
         dgInBytesConsumed = this->in.popCtx ( inctx );
@@ -542,7 +580,9 @@ caStatus casDGClient::processDG ()
             // release the send lock
             //
             pRespHdr->cadg_nBytes = this->out.popCtx ( outctx ) + sizeof ( *pRespHdr );
-            if ( pRespHdr->cadg_nBytes > sizeof ( *pRespHdr ) ) {
+            // if there are not additional messages passed the version header
+            // then discard the message
+            if ( pRespHdr->cadg_nBytes > sizeof ( *pRespHdr ) + sizeof (caHdr) ) {
                 pRespHdr->cadg_addr = pReqHdr->cadg_addr;
                 this->out.commitRawMsg ( pRespHdr->cadg_nBytes );
             }
diff --git a/src/cas/generic/casInternal.h b/src/cas/generic/casInternal.h
index bc9450864..2cfe346ec 100644
--- a/src/cas/generic/casInternal.h
+++ b/src/cas/generic/casInternal.h
@@ -34,7 +34,7 @@
 //
 #include "tsDLList.h"
 #include "resourceLib.h"
-#define CA_MINOR_PROTOCOL_REVISION 10
+#define CA_MINOR_PROTOCOL_REVISION 11
 #include "caProto.h"
 #include "smartGDDPointer.h"
 
diff --git a/src/cas/generic/server.h b/src/cas/generic/server.h
index 2d989a8d8..d2b67974c 100644
--- a/src/cas/generic/server.h
+++ b/src/cas/generic/server.h
@@ -553,7 +553,7 @@ private:
 	//
 	virtual caStatus uknownMessageAction () = 0;
 	caStatus ignoreMsgAction ();
-	caStatus noopAction ();
+	virtual caStatus versionAction ();
 	virtual caStatus eventAddAction ();
 	virtual caStatus eventCancelAction ();
 	virtual caStatus readAction ();
@@ -756,6 +756,7 @@ protected:
 
 private:
     caNetAddr lastRecvAddr;
+    ca_uint32_t seqNoOfReq;
 
 	//
 	// one function for each CA request type
@@ -786,6 +787,8 @@ private:
 	virtual inBufClient::fillCondition osdRecv ( char *pBuf, bufSizeT nBytesReq,
 			fillParameter parm, bufSizeT &nBytesActual, caNetAddr & addr ) = 0;
 
+    caStatus versionAction ();
+
     //
     // cadg
     //