2011/7/24 Andreas Heise aheise@gmx.de:
which kind of Alcatel PBX it is? I use OPTIONS with and without SDP in 200 without problems since several years with Alcatel OmniPCX Enterprise systems.
It's strange as we also work with other Alcatel OXE and OXO with no problems. In this exact case, the PBX performs SIP registration and later sends periodic OPTIONS with "Accept: application/sdp". Since the 200 is replied by my proxy Kamailio, it has no SDP (of course) and the Alcatel PBX ignores the reply and sends retransmissionts until it decides that "the proxy is down".
If you need I could try to get the exact PBX model (and firmware).