diff --git a/ttcn/LibIms_Steps.ttcn b/ttcn/LibIms_Steps.ttcn
index 6f597cd0df7d030df2081cbfd3d6c3c52cdf5a02..89e2661955443c4b8ddff447dc97769c0a0229b6 100644
--- a/ttcn/LibIms_Steps.ttcn
+++ b/ttcn/LibIms_Steps.ttcn
@@ -50,6 +50,28 @@ module LibIms_Steps
           }
         }
         
+        /**
+        ** @desc functions remove own via parameter
+        * @param p_message (request) SIP message to be used to prepair via header
+        * @param p_userprofile user profile
+        */
+       function f_removeOwnViaParameter(in Response p_message) runs on ImsComponent
+       {
+         var integer v_intVia;
+         var Via v_via := c_empty_Via;
+         
+         if (ispresent(p_message.msgHeader.via)) {          
+
+           v_intVia := sizeof(p_message.msgHeader.via.viaBody)-1;
+           
+           for (var integer i := 0; i < v_intVia; i := i + 1)
+           {
+               v_via.viaBody[i] := p_message.msgHeader.via.viaBody[i+1]; 
+           }
+           vc_via := v_via;
+         }
+       }
+        
         /**
         * 
         * @desc functions add new via parameter
@@ -190,11 +212,14 @@ module LibIms_Steps
 			var Response v_response;
 			v_response := vc_response;
 			
-			vc_via:= v_response.msgHeader.via; // TODO via header need to be adapted due to standards
+            vc_caller_To := v_response.msgHeader.toField;
+            vc_to := v_response.msgHeader.toField;
+            vc_contact := v_response.msgHeader.contact;
 			
 			if (ispresent(v_response.msgHeader.recordRoute)) {
-			vc_recordRoute:= v_response.msgHeader.recordRoute; // TODO recordRoute header need to be adapted due to standards
+				vc_recordRoute:= v_response.msgHeader.recordRoute;
 			}
+            f_removeOwnViaParameter(v_response);
 		}// end function f_setHeadersForwardResponse
 
 		/*
@@ -1797,7 +1822,30 @@ module LibIms_Steps
             [] SIPP.receive(mw_Response_Base(c_statusLine183,vc_callId, vc_cSeq))
               { 
                 repeat;
+              }			  
+			  
+            // unexpected CANCEL is acknowledged to avoid retransmissions
+            [] SIPP.receive(mw_CANCEL_Request_Base(?))-> value v_request sender vc_sent_label
+              {
+                setverdict(fail);
+                f_setHeadersOnReceiptOfRequest(v_request);
+                f_send200OK(); 
               } 
+
+            // unexpected BYE is acknowledged to avoid retransmissions
+            [] SIPP.receive(mw_BYE_Request_Base(?))-> value v_request sender vc_sent_label
+              {
+                setverdict(fail);
+                f_setHeadersOnReceiptOfRequest(v_request); 
+                f_send200OK();
+              }
+  
+            [] SIPP.receive(mw_Response_Base(? ,vc_callId, vc_cSeq))-> value vc_response
+              { 
+                log("Response matched in DEFAULT!!!");
+                setverdict(fail);
+                repeat;
+              }
             // any	  
             [] SIPP.receive
             {