How can I enable or disable the sending of OPTIONS requests? (Using TCP rather than UDP, if it should make any difference.)
I’m pursuing, with the manufacturer, resolution of a firmware bug in a phone when using SIP over TCP. When the phone attempts to register to my Asterisk switch (version 1.8 point something), Asterisk sends an OPTIONS request immediately before the 200 OK to the registration, and the OPTIONS request and 200 OK response are merged into the same TCP packet. The phone does not see the 200 OK. However, when the phone manufacturer registers to Asterisk 126.96.36.199, there is no OPTIONS request in the (admittedly very short) network capture they sent me, so they can’t reproduce the problem - which means that, even if they can see what’s wrong in the firmware, they can’t test the solution.
If they can enable OPTIONS requests, the bug can perhaps be fixed.
If I can disable OPTIONS requests, I might be able to work round the bug.
And, yes, I really do need SIP over TCP.