diff --git a/bin/scenario.pl b/bin/scenario.pl
index 49d040e5..327a7a5c 100755
--- a/bin/scenario.pl
+++ b/bin/scenario.pl
@@ -421,7 +421,7 @@ sub generate
             $csv->{scenario}->print($io_scenario, $csv_data);
             if($resp->{register} eq "yes" && $resp->{active} eq "yes")
             {
-                generate_reg($res_id, $test_uuid, $resp->{q});
+                generate_reg($res_id, $test_uuid, $resp->{q}, $resp->{ua});
             }
             if($resp->{foreign} eq "yes")
             {
@@ -436,8 +436,8 @@ sub generate
 
 sub generate_reg
 {
-    my ($num, $test_uuid, $q) = @_;
-    my $vars = { line => $num, test_uuid => $test_uuid, q => $q };
+    my ($num, $test_uuid, $q, $ua) = @_;
+    my $vars = { line => $num, test_uuid => $test_uuid, q => $q, ua => $ua };
     my $fn = File::Spec->catfile($base_check_dir, "sipp_scenario_responder".(sprintf "%02i", $num)."_reg.xml");
     $tt->process($template_reg, $vars, $fn) or die($tt->error(), "\n");
     return;
diff --git a/scenarios/invite_callforward/prefs.json.tt2 b/scenarios/invite_callforward/prefs.json.tt2
index 49103e78..8b31e5f7 100644
--- a/scenarios/invite_callforward/prefs.json.tt2
+++ b/scenarios/invite_callforward/prefs.json.tt2
@@ -1,5 +1,6 @@
 {
     "@invite-callforward.scenarios.test": {
-        "nat_sipping": "no"
+        "nat_sipping": "no",
+        "ua_reject_missing" : 1
     }
 }
diff --git a/scenarios/invite_callforward/scenario.yml b/scenarios/invite_callforward/scenario.yml
index c6c36333..dc5618b4 100644
--- a/scenarios/invite_callforward/scenario.yml
+++ b/scenarios/invite_callforward/scenario.yml
@@ -59,6 +59,7 @@ scenarios:
         username: testuser1003
         domain: invite-callforward.scenarios.test
         register: 'yes'
+        ua: 'KCT SIPP'
   - ip: 127.126.0.1
     username: testuser1002
     domain: invite-callforward.scenarios.test
@@ -67,7 +68,9 @@ scenarios:
         username: testuser1004
         domain: invite-callforward.scenarios.test
         register: 'yes'
+        ua: 'KCT SIPP'
       - ip: 127.1.0.5
         username: testuser1005
         domain: invite-callforward.scenarios.test
         register: 'yes'
+        ua: 'KCT SIPP'
diff --git a/scenarios/invite_callforward/sipp_scenario00.xml b/scenarios/invite_callforward/sipp_scenario00.xml
index b5921982..67de00a8 100644
--- a/scenarios/invite_callforward/sipp_scenario00.xml
+++ b/scenarios/invite_callforward/sipp_scenario00.xml
@@ -11,6 +11,7 @@
       Call-ID: NGCP%[field4 file="callee.csv" line=0]%///[call_id]
       CSeq: 1 INVITE
       Contact: <sip:[field0 file="caller.csv" line=0]@[local_ip]:[local_port]>
+      User-Agent: KCT SIPP
       Max-Forwards: 70
       Content-Type: application/sdp
       Content-Length: [len]
@@ -60,6 +61,7 @@
       Call-ID: NGCP%[field4 file="callee.csv" line=0]%///[call_id]
       CSeq: 2 INVITE
       Contact: <sip:[field0 file="caller.csv" line=0]@[local_ip]:[local_port]>
+      User-Agent: KCT SIPP
       Max-Forwards: 70
       [field1 file="caller.csv" line=0]
       Content-Type: application/sdp
diff --git a/scenarios/invite_callforward/sipp_scenario01.xml b/scenarios/invite_callforward/sipp_scenario01.xml
index 4e7a9ba6..5119786f 100644
--- a/scenarios/invite_callforward/sipp_scenario01.xml
+++ b/scenarios/invite_callforward/sipp_scenario01.xml
@@ -11,6 +11,7 @@
       Call-ID: NGCP%[field4 file="callee.csv" line=0]%///[call_id]
       CSeq: 1 INVITE
       Contact: <sip:[field0 file="caller.csv" line=1]@[local_ip]:[local_port]>
+      User-Agent: KCT SIPP
       Max-Forwards: 70
       Content-Type: application/sdp
       Content-Length: [len]
@@ -60,6 +61,7 @@
       Call-ID: NGCP%[field4 file="callee.csv" line=0]%///[call_id]
       CSeq: 2 INVITE
       Contact: <sip:[field0 file="caller.csv" line=1]@[local_ip]:[local_port]>
+      User-Agent: KCT SIPP
       Max-Forwards: 70
       [field1 file="caller.csv" line=1]
       Content-Type: application/sdp
diff --git a/scenarios/templates/sipp_scenario_responder_reg.xml.tt2 b/scenarios/templates/sipp_scenario_responder_reg.xml.tt2
index 4273b006..f8154697 100644
--- a/scenarios/templates/sipp_scenario_responder_reg.xml.tt2
+++ b/scenarios/templates/sipp_scenario_responder_reg.xml.tt2
@@ -12,6 +12,7 @@
       Call-ID: NGCP%[field4 file="callee.csv" line=0]%///[call_id]
       CSeq: 1 REGISTER
       Contact: sip:[field0 file="callee.csv" line=[% line -%]]@[local_ip]:[local_port];transport=[transport][% IF q %];q=[% q %][% END %]
+      [% IF ua %]User-Agent: [% ua %][% END %]
       Expires: 600
       Max-Forwards: 70
       Content-Length: 0
@@ -36,6 +37,7 @@
       CSeq: 2 REGISTER
       [field2 file="callee.csv" line=[% line -%]]
       Contact: sip:[field0 file="callee.csv" line=[% line -%]]@[local_ip]:[local_port];transport=[transport][% IF q %];q=[% q %][% END %]
+      [% IF ua %]User-Agent: [% ua %][% END %]
       Expires: 600
       Max-Forwards: 70
       Content-Length: 0