[OpenSIPS-Users] TLS to UDP, record route

[John Quick]

Ah, topology hiding changes everything. I did not appreciate that it was involved.

John Quick
Smartvox Limited


From: Miha <miha at softnet.si> 
Sent: 18 May 2021 11:56
To: john.quick at smartvox.co.uk; users at lists.opensips.org
Subject: Re: [OpenSIPS-Users] TLS to UDP, record route

hello John

i have found what was causing the issue. is was topology hiding when ACK was received by opensips. 


thank you for all your help and time :)

br
miha
John Quick je 5/18/2021 ob 11:15 AM napisal:
Miha

Altering the text in the Record-Route headers with subst() function is not
the correct approach.
I believe the problem is that you are not inserting the correct RR headers
in the first place.
If you get the RR headers right then it will also fix the problem with ACK
using the wrong protocol.
This pseudo-code snippet illustrates what is required when adding RR headers
to the initial INVITE request:

if (INVITE-from-Teams-Proxy-to-us) {
    record_route_preset("IP:port", "SBC_FQDN:5061;transport=tls");
    add_rr_param(";r2=on");
} else if (INVITE-from-us-to-Teams-Proxy) {
    record_route_preset( "SBC_FQDN:5061;transport=tls", "IP:port");
    add_rr_param(";r2=on");
} else
    record_route();

Don't insert any RR headers when handling loose-routed requests.

I tried to explain all this stuff in a number of articles. Here are the
links:
https://kb.smartvox.co.uk/opensips/opensips-as-ms-teams-sbc/
https://kb.smartvox.co.uk/opensips/nat-contact-and-via-fixing-in-sip-part-4/
https://kb.smartvox.co.uk/opensips/contact-and-record-route-headers-explaine
d/

John Quick
Smartvox Limited