Re: [SR-Users] MS Teams Direct routing with kamailio

Hi Karsten, Try this: event_route[tm:local-request] { if(is_method("OPTIONS")) { append_hf("Contact: foobar\r\n"); } } U YYYYY:5060 -> XXXXXX:5060 OPTIONS sip:sip.XXXXX.microsoft.com SIP/2.0. Via: SIP/2.0/UDP YYYYY;branch=z9hG4bK20ab.bd499990000000000000000000000000.0. To: <sip:sip.XXXXX.microsoft.com>. From: <sip:dispatcher@localhost>;tag=3393f0703fb0ccaca74109ff37de39f5-50a8. CSeq: 10 OPTIONS. Call-ID: 6b3a52797fe20b99-14352(a)127.0.0.1. Max-Forwards: 70. Content-Length: 0. User-Agent: Kamailio. Contact: foobar. Cheers, Henning -- Henning Westerholt - https://skalatan.de/blog/ Kamailio services - https://skalatan.de/services From: sr-users &lt;sr-users-bounces(a)lists.kamailio.org&gt; On Behalf Of Karsten Horsmann Sent: Tuesday, October 22, 2019 6:24 PM To: Kamailio (SER) - Users Mailing List &lt;sr-users(a)lists.kamailio.org&gt; Subject: [SR-Users] MS Teams Direct routing with kamailio Hello List, i search for the right place in kamailio to manipulate the dispatcher OPTIONS packets to add an Contact header. For uac generated traffic i can use the event_route[tm:local-request] from the tm module. But how can i manipulate kamailio *self* generated OPTION pings from the dispatcher? OPTIONS request for MS Teams must contain the Contact header of such a format: Contact: <sip:SBC_FQDN:5061;transport=tls> I follow this guide (for opensips) and try to adapt that step by step to kamailio: https://blog.opensips.org/2019/09/16/opensips-as-ms-teams-sbc/ CentOS 7 / kamailio 5.2.x (and maybe soon 5.3.x) / rtpengine -- Cheers *Karsten Horsmann*