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<p>Hello,</p>
<p>I saw there are some topics on this already and carefully walked
through all of them, but can't solve following issue.</p>
<p>For a reason I do need that in Record-Route header sent to
endpoint would present FQDN. If it matters, it's UDP/WSS
conversion done on Kamailio.</p>
<p>So, scheme is quite simple<br>
</p>
<p>Enpoint A ->UDP-> Kamailio ->WSS-> Endpoint B (NAT)<br>
</p>
<p>Main issue here, that if in Record-Route headers it's FQDN, but
not IP addresses, on a new transactions with a dialog (ACK on 200,
PRACK, BYE), Kamailio<b> loose_route()</b> function resolves
address of destination not current dialog, but actual R-URI (or
itself, if R-URI is something from WebRTC world) that is not
correct due to NAT.<br>
</p>
<p>If in RR headers IP addresses are present - all is working as
expected.</p>
<p>As an example (RR with FQDN)<br>
</p>
<p>B answers 200</p>
<p><font face="Courier New, Courier, monospace">SIP/2.0 200 OK<br>
Record-Route:
<a class="moz-txt-link-rfc2396E" href="sip:KAMAILIO_FQDN:8089;transport=ws;r2=on;lr=on;ftag=0a3e31a6-96ad-42d0-9310-81b35cedbd3d;nat=wss"><sip:KAMAILIO_FQDN:8089;transport=ws;r2=on;lr=on;ftag=0a3e31a6-96ad-42d0-9310-81b35cedbd3d;nat=wss></a><br>
Record-Route:
<a class="moz-txt-link-rfc2396E" href="sip:KAMAILIO_FQDN;r2=on;lr=on;ftag=0a3e31a6-96ad-42d0-9310-81b35cedbd3d;nat=wss"><sip:KAMAILIO_FQDN;r2=on;lr=on;ftag=0a3e31a6-96ad-42d0-9310-81b35cedbd3d;nat=wss></a><br>
Via: SIP/2.0/UDP <A_IP_ADDRESS>:5060;received=A IP
ADDRESS;rport=5060;branch=z9hG4bKPj67fb6d86-97d7-4231-995b-e54b0f62881e<br>
To: <<a class="moz-txt-link-freetext" href="sip:88290@">sip:88290@</a><KAMAILIO_FQDN>>;tag=hvra7mj3q0<br>
From:
<<a class="moz-txt-link-freetext" href="sip:+XXXX7688881@">sip:+XXXX7688881@</a><KAMAILIO_FQDN>>;tag=0a3e31a6-96ad-42d0-9310-81b35cedbd3d<br>
Call-ID: 46f44741-d155-4dd5-8fd8-78e540fc1acb<br>
CSeq: 18326 INVITE<br>
Contact: <a class="moz-txt-link-rfc2396E" href="sip:88290@toleivu2gdbh.invalid;transport=wss"><sip:88290@toleivu2gdbh.invalid;transport=wss></a><br>
Allow: ACK,CANCEL,INVITE,MESSAGE,BYE,OPTIONS,INFO,NOTIFY,REFER<br>
Supported: outbound<br>
Content-Type: application/sdp<br>
Content-Length: 817</font></p>
<p><br>
</p>
<p>ACK looks like</p>
<p><font face="Courier New, Courier, monospace">ACK
<a class="moz-txt-link-freetext" href="sip:88290@toleivu2gdbh.invalid;transport=wss">sip:88290@toleivu2gdbh.invalid;transport=wss</a> SIP/2.0<br>
Via: SIP/2.0/UDP
A_IP_ADDRESS:5060;rport;branch=z9hG4bKPj8d05548a-91ef-4332-8617-32f8eeebf8f2<br>
From:
<a class="moz-txt-link-rfc2396E" href="sip:88881@A_IP_ADDRESS"><sip:88881@A_IP_ADDRESS></a>;tag=0a3e31a6-96ad-42d0-9310-81b35cedbd3d<br>
To: <a class="moz-txt-link-rfc2396E" href="sip:88290@KAMAILIO_FQDN"><sip:88290@KAMAILIO_FQDN></a>;tag=hvra7mj3q0<br>
Call-ID: 46f44741-d155-4dd5-8fd8-78e540fc1acb<br>
CSeq: 18326 ACK<br>
Route:
<a class="moz-txt-link-rfc2396E" href="sip:FQDN;lr;r2=on;ftag=0a3e31a6-96ad-42d0-9310-81b35cedbd3d;nat=wss"><sip:FQDN;lr;r2=on;ftag=0a3e31a6-96ad-42d0-9310-81b35cedbd3d;nat=wss></a><br>
Route:
<a class="moz-txt-link-rfc2396E" href="sip:FQDN:8089;transport=ws;lr;r2=on;ftag=0a3e31a6-96ad-42d0-9310-81b35cedbd3d;nat=wss"><sip:FQDN:8089;transport=ws;lr;r2=on;ftag=0a3e31a6-96ad-42d0-9310-81b35cedbd3d;nat=wss></a><br>
Max-Forwards: 70<br>
User-Agent: Asterisk PBX 13.33.0<br>
Content-Length: 0</font><br>
</p>
<p>And Kamailio on <b>loose_route()</b> loops ACK to itself. (with
result of function == 1)<br>
</p>
<p>In a case if in Record-Route/Route headers just IP address of
Kamailio present, all works as expected, but it's not really
behavior I want to achieve.</p>
<p>I've tried to play with <b>record_route_preset("...")</b>
specifying only WSS part (as suggested in
<a class="moz-txt-link-freetext" href="https://skalatan.de/de/blog/kamailio-sbc-teams">https://skalatan.de/de/blog/kamailio-sbc-teams</a>) with FQDN, but no
luck.</p>
<p>Also wanted to try approach using record_route_preset() function
in branch route, but it was working only with first branch, not
affecting others (but I assume having different RR headers across
branches is not a good idea)</p>
<pre class="moz-signature" cols="72">--
Regards,
Igor</pre>
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