so if you want your wonderful app work with others it might be good to interop with Asterisk ....
And after asterisk, I should do freeswitch, kamilio, 3cx, opensip, openser, freepbx, etc
I am only interested right now in SIP for telephony integration. I support a SIP registration service (your phone can register with openfire meetings), sip proxy and direct SIP invites. Asterisk is first and foremost a multiple protocol PBX and not a SIP server.
The underlying SIP stack for jigasi and ofmeet is NIST SIP 1.2. Jigasi is using a custom proxy that manages multiple clients which are a cut-down version of the sip client in the jitsi client that can handle multiple SSRCs. In ofmeet, I am using a SIP proxy/registrar using the kelpie implementation as my starting point.