[SR-Users] Routing incoming calls to Asterisk trunk

Hello,

I'd setup a test environment where Kamailio accepts external invites and routes them to an internal Asterisk (actually working as an SBC). My dialplan works fine routing the INVITE to the internal Asterisk, but the SIP message goes into the defaul sip context (the one configured in sip general), and not in the context defined for the sip trunk between Kamailio and Asterisk.

The sip trunk is configured like this:

[kamailio] disallow=all host=kamailio port=5060 insecure=port,invite type=friend context=from-sip-external fromdomain=mydomain qualify=yes allow=alaw allow=g722

So I expect that all the sip invites coming from kamailio should be executed in from-sip-external context.

But it doesn't work like this since each invite goes in the default context.

The invite that goes to Asterisk is like this

<--- SIP read from kamailio-external:5060 ---> INVITE sip:extension@asterisk:5060;transport=UDP SIP/2.0 Record-Route: sip:kamailio-external:5060;nat=yes;ftag=905e4921;lr=on Via: SIP/2.0/UDP kamailio-external:5060;branch=z9hG4bK277a.aea3ad87.0 Via: SIP/2.0/UDP caller:28021;rport=28019;received=caller;branch=z9hG4bK-d8754z-d11f1fa1d0fb2ab4-1---d8754z- Max-Forwards: 69 Contact: sip:524@caller:28019;transport=UDP To: sip:extension@kamailio-external From: sip:524@caller:28007;tag=905e4921 Call-ID: YzEzMDM1NDZhZTllMTRiMDJmY2MyZTE0ZWZjMzE5OTc. CSeq: 1 INVITE Allow: INVITE, ACK, CANCEL, BYE, NOTIFY, REFER, MESSAGE, OPTIONS, INFO, SUBSCRIBE Supported: replaces, norefersub, extended-refer, timer, X-cisco-serviceuri User-Agent: Z 3.2.21357 r21367 Allow-Events: presence, kpml Content-Type: application/sdp Content-Length: 260

What I think is that in the sip message there is no information about kamailio internal ip address but only about kamailio-external address and then Asterisk put it into the default context. If this is the reason, should I change the trunk ip address in Asterisk and should I do some manipulation on the incoming packet on kamailio? Or maybe I should use kamailio-external as fromdomain in the trunk configuration?

Thanks.