When using nat_uac_test("3"), there is a particular REGISTER message that my kamailio server receives where the source and via addresses are different, but this function seems to return false (and then no nat correction is applied).  I have included the register message below.  Is there an obvious reason this is not triggering the nat_uac_test?  Or can anyone share how they would usually debug a situation like this?  Any help/advice would be appreciated.

Thank you!


Example captured Register message:

REGISTER sip:test1.test.com:5060 SIP/2.0 
Call-ID: 3b0400ca43e28f78f3e6dc945a084b88@192.xx.xxx.xxx 
CSeq: 1418 REGISTER 
From: "Joe" <sip:xxxyyyzzzz@test1.test.com>;tag=2163936191 
To: "Joe" <sip:xxxyyyzzzz@test1.test.com> 
Via: SIP/2.0/UDP 96.xxx.xxx.xxx:33745;rport;branch=z9hG4bKf5s1p`n3TRv5TZx5RXy.RVv+JPz8Nat*UX!8KRx4SRx 
Via: SIP/2.0/UDP 192.xx.xxx.xxx:33745;branch=z9hG4bKeb263246c44095f072d8167dd0c7987a343134;rport 
Max-Forwards: 70 
User-Agent: SIPAUA/0.1.001 
Contact: "Joe" <sip:xxxyyyzzzz@192.xx.xxx.xxx:33745;transport=udp> 
Expires: 3600 
Authorization: Digest username="xxxyyyzzzz",realm="test1.test.com",nonce="UsDqxVLA6ZlvIrO3TsqCtm9X3vqY8405",uri="sip:test1.test.com:5060",response="769d1e6f2fd36cf040503f9f079279a0" 
Content-Length: 0 

Associated lines from kamailio log:

[kamailio]# grep 3b0400ca43e28f78f3e6dc945a084b88@192.xx.xxx.xxx kamailio.log
Dec 30 03:33:45 sip-01 kamailio[20489]: INFO: <script>: 3b0400ca43e28f78f3e6dc945a084b88@192.xx.xxx.xxx|start|recieved UDP request REGISTER sip:test1.test.com
Dec 30 03:33:45 sip-01 kamailio[20489]: INFO: <script>: 3b0400ca43e28f78f3e6dc945a084b88@192.xx.xxx.xxx|log|source 96.xxx.xxx.xxx:33745
Dec 30 03:33:45 sip-01 kamailio[20489]: INFO: <script>: 3b0400ca43e28f78f3e6dc945a084b88@192.xx.xxx.xxx|log|from sip:xxxyyyzzzz@test1.test.com
Dec 30 03:33:45 sip-01 kamailio[20489]: INFO: <script>: 3b0400ca43e28f78f3e6dc945a084b88@192.xx.xxx.xxx|log|to sip:xxxyyyzzzz@test1.test.com
Dec 30 03:33:45 sip-01 kamailio[20489]: INFO: <script>: 3b0400ca43e28f78f3e6dc945a084b88@192.xx.xxx.xxx|log|originated from external sources
Dec 30 03:33:45 sip-01 kamailio[20489]: INFO: <script>: 3b0400ca43e28f78f3e6dc945a084b88@192.xx.xxx.xxx|end|issued new auth challenge to new registration attempt
Dec 30 03:33:45 sip-01 kamailio[20495]: INFO: <script>: 3b0400ca43e28f78f3e6dc945a084b88@192.xx.xxx.xxx|start|recieved UDP request REGISTER sip:test1.test.com:5060
Dec 30 03:33:45 sip-01 kamailio[20495]: INFO: <script>: 3b0400ca43e28f78f3e6dc945a084b88@192.xx.xxx.xxx|log|source 96.xxx.xxx.xxx:33745
Dec 30 03:33:45 sip-01 kamailio[20495]: INFO: <script>: 3b0400ca43e28f78f3e6dc945a084b88@192.xx.xxx.xxx|log|from sip:xxxyyyzzzz@test1.test.com
Dec 30 03:33:45 sip-01 kamailio[20495]: INFO: <script>: 3b0400ca43e28f78f3e6dc945a084b88@192.xx.xxx.xxx|log|to sip:xxxyyyzzzz@test1.test.com
Dec 30 03:33:45 sip-01 kamailio[20495]: INFO: <script>: 3b0400ca43e28f78f3e6dc945a084b88@192.xx.xxx.xxx|log|originated from external sources
Dec 30 03:33:45 sip-01 kamailio[20495]: DEBUG: <script>: 3b0400ca43e28f78f3e6dc945a084b88@192.xx.xxx.xxx|log|authenticated xxxyyyzzzz@test1.test.com via cached SIP creds