Hi!
Currently we have the following logic in our Kamailio routing script. On incoming INVITE, we lookup() the location of called party, then we analyse the updated Request-URI ($ru) regarding callee contact protocol: is it websocket-based or not, to distinguish web-based useragents from classic SIP agents and provide RTP profiles interconnection with rtpengine (RTP/SAVPF for web-based, RTP/AVPF for the rest). After that, we relay the mangled INVITE to callee location(s) with t_relay().
The issue arises when callee has both websocket-based and classic useragents registered simultaneously. According to lookup() manual, it replaces Req-URI with just one contact, and somehow also attach metainformation about additional locations, so that t_relay() forks the call.
lookup() does not provide the possibility to fork the execution of routing script, so that we could execute our routing logic described above. But I would love this to be possible, because the only alternative way for calling to multiple locations seems to be the serial forking described in TM module manual. But we don't need serial calling contact-by-contact, waiting for call failures, we need parallel calling to all available user locations.
So we need an advice how to go. Is there a way to implement what we need at scripting level, or should this feature be implemented in Kamailio code (or is it already there?). Thanks in advance for any help.