diff --git a/scenarios/invite_concurrent_max_out_per_account/0001_test.yml.tt2 b/scenarios/invite_concurrent_max_out_per_account/0001_test.yml.tt2
index 22220999..48e36304 100644
--- a/scenarios/invite_concurrent_max_out_per_account/0001_test.yml.tt2
+++ b/scenarios/invite_concurrent_max_out_per_account/0001_test.yml.tt2
@@ -22,7 +22,7 @@ flow:
   - exit|ROUTE_EXIT:
 sip_in:
   - '^INVITE sip:[% scenarios.0.responders.0.username %]@'
-  - 'Contact: sip:testuser1002@'
+  - 'Contact: <sip:[% scenarios.0.username %]@[% scenarios.0.ip %]:[% scenarios.0.port %](;[^>]+)?>'
   - 'To: <sip:[% scenarios.0.responders.0.username %]@'
   - 'CSeq: 1 INVITE'
   - 'Max-Forwards: 69'
diff --git a/scenarios/invite_concurrent_max_out_per_account/0003_test.yml.tt2 b/scenarios/invite_concurrent_max_out_per_account/0003_test.yml.tt2
index 52eb5efc..3a025840 100644
--- a/scenarios/invite_concurrent_max_out_per_account/0003_test.yml.tt2
+++ b/scenarios/invite_concurrent_max_out_per_account/0003_test.yml.tt2
@@ -183,7 +183,7 @@ flow:
       ]
 sip_in:
   - '^INVITE sip:[% scenarios.0.responders.0.username %]@'
-  - 'Contact: sip:testuser1002@'
+  - 'Contact: <sip:[% scenarios.0.username %]@[% scenarios.0.ip %]:[% scenarios.0.port %](;[^>]+)?>'
   - 'CSeq: 2 INVITE'
   - 'Max-Forwards: 69'
   - 'Content-Type: application/sdp'
diff --git a/scenarios/invite_concurrent_max_out_per_account/0013_test.yml.tt2 b/scenarios/invite_concurrent_max_out_per_account/0013_test.yml.tt2
index 710e07cb..e168fefd 100644
--- a/scenarios/invite_concurrent_max_out_per_account/0013_test.yml.tt2
+++ b/scenarios/invite_concurrent_max_out_per_account/0013_test.yml.tt2
@@ -25,7 +25,7 @@ flow:
   - exit|ROUTE_EXIT:
 sip_in:
   - '^INVITE'
-  - 'Contact: sip:testuser1002@'
+  - 'Contact: <sip:[% scenarios.0.username %]@[% scenarios.0.ip %]:[% scenarios.0.port %](;[^>]+)?>'
   - 'CSeq: 3 INVITE'
   - 'Max-Forwards: 69'
   - 'Content-Type: application/sdp'
diff --git a/scenarios/invite_concurrent_max_out_per_account/0021_test.yml.tt2 b/scenarios/invite_concurrent_max_out_per_account/0021_test.yml.tt2
index 86660dde..d7423960 100644
--- a/scenarios/invite_concurrent_max_out_per_account/0021_test.yml.tt2
+++ b/scenarios/invite_concurrent_max_out_per_account/0021_test.yml.tt2
@@ -22,7 +22,7 @@ flow:
   - exit|ROUTE_EXIT:
 sip_in:
   - '^INVITE sip:[% scenarios.0.responders.1.username %]@'
-  - 'Contact: sip:testuser1002@'
+  - 'Contact: <sip:[% scenarios.0.username %]@[% scenarios.0.ip %]:[% scenarios.0.port %](;[^>]+)?>'
   - 'To: <sip:[% scenarios.0.responders.1.username %]@'
   - 'CSeq: 1 INVITE'
   - 'Max-Forwards: 69'
diff --git a/scenarios/invite_concurrent_max_out_per_account/0023_test.yml.tt2 b/scenarios/invite_concurrent_max_out_per_account/0023_test.yml.tt2
index c96093d9..186b631d 100644
--- a/scenarios/invite_concurrent_max_out_per_account/0023_test.yml.tt2
+++ b/scenarios/invite_concurrent_max_out_per_account/0023_test.yml.tt2
@@ -138,7 +138,7 @@ flow:
   - exit|ROUTE_EXIT:
 sip_in:
   - '^INVITE sip:[% scenarios.0.responders.1.username %]@'
-  - 'Contact: sip:testuser1002@'
+  - 'Contact: <sip:[% scenarios.0.username %]@[% scenarios.0.ip %]:[% scenarios.0.port %](;[^>]+)?>'
   - 'From: <sip:testuser1002@'
   - 'To: <sip:[% scenarios.0.responders.1.username %]@'
   - 'CSeq: 2 INVITE'
diff --git a/scenarios/invite_concurrent_max_out_per_account/0025_test.yml.tt2 b/scenarios/invite_concurrent_max_out_per_account/0025_test.yml.tt2
index 84c2af3e..81c14b61 100644
--- a/scenarios/invite_concurrent_max_out_per_account/0025_test.yml.tt2
+++ b/scenarios/invite_concurrent_max_out_per_account/0025_test.yml.tt2
@@ -28,7 +28,7 @@ flow:
   - exit|ROUTE_EXIT:
 sip_in:
   - '^BYE'
-  - 'Contact: sip:testuser1002@'
+  - 'Contact: <sip:[% scenarios.0.username %]@[% scenarios.0.ip %]:[% scenarios.0.port %](;[^>]+)?>'
   - 'From: <sip:testuser1002@'
   - 'To: <sip:[% scenarios.0.responders.0.username %]@'
   - 'CSeq: 6 BYE'
diff --git a/scenarios/invite_concurrent_max_out_per_account/sipp_scenario00.xml b/scenarios/invite_concurrent_max_out_per_account/sipp_scenario00.xml
index a132af87..7fce076a 100644
--- a/scenarios/invite_concurrent_max_out_per_account/sipp_scenario00.xml
+++ b/scenarios/invite_concurrent_max_out_per_account/sipp_scenario00.xml
@@ -10,7 +10,7 @@
       To: <sip:[field0 file="callee.csv" line=0]@[field3 file="callee.csv" line=0]>
       Call-ID: NGCP%[field4 file="callee.csv" line=0]%///[call_id]
       CSeq: 1 INVITE
-      Contact: sip:[field0 file="caller.csv"]@[local_ip]:[local_port]
+      Contact: <sip:[field0 file="caller.csv"]@[local_ip]:[local_port]>
       Max-Forwards: 70
       Content-Type: application/sdp
       Content-Length: [len]
@@ -41,7 +41,7 @@
       To: <sip:[field0 file="callee.csv" line=0]@[field3 file="callee.csv" line=0]>[peer_tag_param]
       Call-ID: NGCP%[field4 file="callee.csv" line=0]%///[call_id]
       CSeq: 1 ACK
-      Contact: sip:[field0 file="caller.csv"]@[local_ip]:[local_port]
+      Contact: <sip:[field0 file="caller.csv"]@[local_ip]:[local_port]>
       Max-Forwards: 70
       Content-Length: 0
 
@@ -59,7 +59,7 @@
       To: <sip:[field0 file="callee.csv" line=0]@[field3 file="callee.csv" line=0]>
       Call-ID: NGCP%[field4 file="callee.csv" line=0]%///[call_id]
       CSeq: 2 INVITE
-      Contact: sip:[field0 file="caller.csv"]@[local_ip]:[local_port]
+      Contact: <sip:[field0 file="caller.csv"]@[local_ip]:[local_port]>
       Max-Forwards: 70
       [field1 file="caller.csv"]
       Content-Type: application/sdp
@@ -99,7 +99,7 @@
       [last_Call-ID:]
       [routes]
       CSeq: [cseq] ACK
-      Contact: sip:[field0 file="caller.csv"]@[local_ip]:[local_port]
+      Contact: <sip:[field0 file="caller.csv"]@[local_ip]:[local_port]>
       Max-Forwards: 70
       Content-Length: 0
 
@@ -118,7 +118,7 @@
       [last_Call-ID:]
       [routes]
       CSeq: [cseq] INVITE
-      Contact: sip:[field0 file="caller.csv"]@[local_ip]:[local_port]
+      Contact: <sip:[field0 file="caller.csv"]@[local_ip]:[local_port]>
       Max-Forwards: 70
       [field1 file="caller.csv"]
       Content-Type: application/sdp
@@ -157,7 +157,7 @@
       [last_Call-ID:]
       [routes]
       CSeq: [cseq] ACK
-      Contact: sip:[field0 file="caller.csv"]@[local_ip]:[local_port]
+      Contact: <sip:[field0 file="caller.csv"]@[local_ip]:[local_port]>
       Max-Forwards: 70
       Content-Length: 0
 
@@ -175,7 +175,7 @@
       To: <sip:[field0 file="callee.csv" line=1]@[field3 file="callee.csv" line=1]>
       Call-ID: NGCP%[field4 file="callee.csv" line=0]%NEW///[call_id]
       CSeq: 1 INVITE
-      Contact: sip:[field0 file="caller.csv"]@[local_ip]:[local_port]
+      Contact: <sip:[field0 file="caller.csv"]@[local_ip]:[local_port]>
       Max-Forwards: 70
       Content-Type: application/sdp
       Content-Length: [len]
@@ -206,7 +206,7 @@
       To: <sip:[field0 file="callee.csv" line=1]@[field3 file="callee.csv" line=1]>[peer_tag_param]
       Call-ID: NGCP%[field4 file="callee.csv" line=0]%NEW///[call_id]
       CSeq: 1 ACK
-      Contact: sip:[field0 file="caller.csv"]@[local_ip]:[local_port]
+      Contact: <sip:[field0 file="caller.csv"]@[local_ip]:[local_port]>
       Max-Forwards: 70
       Content-Length: 0
 
@@ -224,7 +224,7 @@
       To: <sip:[field0 file="callee.csv" line=1]@[field3 file="callee.csv" line=1]>
       Call-ID: NGCP%[field4 file="callee.csv" line=0]%NEW///[call_id]
       CSeq: 2 INVITE
-      Contact: sip:[field0 file="caller.csv"]@[local_ip]:[local_port]
+      Contact: <sip:[field0 file="caller.csv"]@[local_ip]:[local_port]>
       Max-Forwards: 70
       [field1 file="caller.csv"]
       Content-Type: application/sdp
@@ -266,7 +266,7 @@
       To: <sip:[field0 file="callee.csv" line=1]@[field3 file="callee.csv" line=1]>;tag=[$3]
       Call-ID: NGCP%[field4 file="callee.csv" line=0]%NEW///[call_id]
       CSeq: 2 ACK
-      Contact: sip:[field0 file="caller.csv"]@[local_ip]:[local_port]
+      Contact: <sip:[field0 file="caller.csv"]@[local_ip]:[local_port]>
       Max-Forwards: 70
       Content-Length: 0
 
@@ -284,7 +284,7 @@
       To: <sip:[field0 file="callee.csv" line=0]@[field3 file="callee.csv" line=0]>;tag=[$2]
       Call-ID: NGCP%[field4 file="callee.csv" line=0]%///[call_id]
       CSeq: [cseq] BYE
-      Contact: sip:[field0 file="caller.csv"]@[local_ip]:[local_port]
+      Contact: <sip:[field0 file="caller.csv"]@[local_ip]:[local_port]>
       [routes]
       Max-Forwards: 70
       Content-Length: 0