Hi,
I am trying to get Kamailio working with a third party SIP provider. This provider pings Kamailio with OPTIONS messages, but Kamailio does not answer correctly: the Call-ID and the tags change where they should not. Here is an example:
Third party SIP server:
OPTIONS sip:false.sip.provider:5060 SIP/2.0 Via: SIP/2.0/UDP 197.17.144.4:5060;branch=z9hG4bK8e45ac1463a From: sip:197.17.144.4;tag=1669836943 To: sip:false.sip.provider Date: Fri, 07 Aug 2015 12:34:37 GMT Call-ID: a012e080-5c41a5ce-8e5-38512c6@197.17.144.4 User-Agent: Cisco-CUCM10.5 CSeq: 101 OPTIONS Contact: sip:197.17.144.4:5060 Max-Forwards: 0 Content-Length: 0
Kamailio's answer:
SIP/2.0 200 OK Via: SIP/2.0/UDP 197.17.144.4:5060;branch=z9hG4bK93e5f072f5f;received=174.37.217.1 From: sip:197.17.144.4;tag=298911055 To: sip:false.sip.provider;tag=b27e1a1d33761e85846fc98f5f3a7e58.8c24 Call-ID: 2defcb00-5c41aa17-93f-38512c6@197.17.144.4 CSeq: 101 OPTIONS Server: kamailio (4.3.1 (x86_64/linux)) Content-Length: 0
You can see that the Call-ID change from "a012e080-5c41a5ce-8e5-38512c6" to "2defcb00-5c41aa17-93f-38512c6". Likewise, the From tag change ("1669836943" to "298911055"). What could be the reason for this ? Moreover I think Kamailio should add the field Allow (with INVITE,ACK,BYE,CANCEL,INFO,OPTIONS,REFER,SUBSCRIBE,NOTIFY), but it does not.
I should mention that I had to modify /kamailio.cfg/ to have Kamailio answer to OPTIONS messages (I added *the code in bold*):
if (*!is_method("OPTIONS") && *!mf_process_maxfwd_header("10")) { sl_send_reply("483","Too Many Hops"); exit; }
if(is_method("OPTIONS") && uri==myself && $rU==$null) { *#* sl_send_reply("200","Keepalive"); *options_reply();* exit; }
Maybe this hack replaces an expected behavior that I failed to see/configure ?
Thanks, Jean-Marie.