[SR-Users] nat_uac_test question

[Daniel-Constantin Mierla]

Hello,

what is the version are you using?

Just as side note, the received parameter is also required by the
presence of rport parameter in incoming request -- I know you referred
to the one in Contact, just wanted to underline the difference.

Cheers,
Daniel

On 09/07/15 16:22, Kristian Kielhofner wrote:
> Hello,
>
>   I'm testing some basic flags with nat_uac_test. I have the following
> (rudimentary) script:
>
> route[NATDETECT] {
> #!ifdef WITH_NAT
>         if (has_body("application/sdp")) {
>                 if (nat_uac_test("18")) {
>                         xlog("SCRIPT: SDP NAT Detected\n");
>                         setflag(6);
>                 }
>         } else {
>                 if (nat_uac_test("2")) {
>                         xlog("SCRIPT: Other NAT Detected\n");
>                         setflag(6);
>                 }
>         }
>
>         if (isflagset(6)) {
>                 xlog("SCRIPT: NAT detected\n");
>                 force_rport();
>                 if (is_method("REGISTER")) {
>                         fix_nated_register();
>                 } else {
>                         if(is_first_hop())
>                                 set_contact_alias();
>                 }
>                 setflag(FLT_NATS);
>         }
> #!endif
>         return;
> }
>
>   When presented with this REGISTER message (ngrep output, so first
> line is IP source address and port):
>
> U 192.168.113.17:6060 -> 192.168.113.11:5060
> REGISTER sip:192.168.113.11;transport=udp SIP/2.0.
> Via: SIP/2.0/UDP 192.168.113.17:6060;branch=z9hG4bKOzvuzaIa;rport.
> From: <sip:user_1 at 192.168.113.11>;tag=3F785909-559E7E9F0009321B-B5BFFB40.
> To: <sip:user_1 at 192.168.113.11>.
> CSeq: 10 REGISTER.
> Call-ID: 1C193C6B-559E7E9F00093255-B5BFFB40.
> Max-Forwards: 70.
> User-Agent: FreeSWITCH.
> Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, INFO, UPDATE,
> REGISTER, REFER, NOTIFY.
> Supported: timer, path, replaces.
> Contact: <sip:gw+sip0 at 10.40.47.190:5080;transport=udp;gw=sip0>;expires=3600.
> Content-Length: 0.
> .
>
>
> U 192.168.113.11:5060 -> 192.168.113.17:6060
> SIP/2.0 200 OK.
> Via: SIP/2.0/UDP
> 192.168.113.17:6060;branch=z9hG4bKOzvuzaIa;rport=6060;received=192.168.113.17.
> From: <sip:user_1 at 192.168.113.11>;tag=3F785909-559E7E9F0009321B-B5BFFB40.
> To: <sip:user_1 at 192.168.113.11>;tag=b27e1a1d33761e85846fc98f5f3a7e58.1045.
> CSeq: 10 REGISTER.
> Call-ID: 1C193C6B-559E7E9F00093255-B5BFFB40.
> Contact: <sip:gw+sip0 at 10.40.47.190:5080;transport=udp;gw=sip0>;expires=3600;received="sip:192.168.113.17:6060".
> Server: Kamailio.
> Content-Length: 0.
> .
>
> Log output:
>
> Jul  9 10:00:41 kamailio /usr/sbin/kamailio[3886]: ERROR: <script>:
> SCRIPT: Other NAT Detected
> Jul  9 10:00:41 kamailio /usr/sbin/kamailio[3886]: ERROR: <script>:
> SCRIPT: NAT detected
>
>
>   Log output, the presence of the added "received" parameter in the
> returned Contact, etc show that NAT was detected. However, the IP
> source and port match the one presented in the Via header.
>
>   What am I missing here?
>
> Thanks!
>

-- 
Daniel-Constantin Mierla
http://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda
Book: SIP Routing With Kamailio - http://www.asipto.com