[OpenSIPS-Users] UPDATE with SDP after 183 Session Progress, allowed?

[Andreas Sikkema]

Hi,

We're running a quite old version of OpenSIPS (1.4 era) and I am
seeing a rather weird logging when OpenSIPS receives an UPDATE
message:
Jun 14 07:18:26 sip2 /usr/sbin/opensips[2023]:
CRITICAL:dialog:log_next_state_dlg: bogus event 8 in state 2 for dlg
0xb073bbf0 [607:2089897759] with clid
'1382180-54356afb-13c4-50029-12967-1b6df2a9-12967' and tags
'1324910-54356afb-13c4-50029-12967-ddac1d7-12967' ''

One scenario is where our Cisco AS5350 is sending UPDATE messages when
a call is being sent from SIP to PSTN via the gateway. This happens
before the call is answered  after a 183 Session Progress has been
handled. So far I haven't seen any issues from receiving this form of
UPDATE message in this, apparently not quite expected, place during
the call.

The other scenario does give issues. Here a call is made that is
essentially the same, but the *calling* party sends an UPDATE message
containing SDP, we get the same line in the logfile, the UPDATE is
passed on to the recipient, but there's no change to the SDP by the
mediaproxy dispatcher. The resulting 200 OK (for the UPDATE) from the
recipient also contains SDP but is again not handled by the mediaproxy
dispatcher and therefore we get one way audio.

I do have an ACME Packet SBC that is sending the UPDATE containing the
SDP. I could, in theory, remove the whole SDP body, but that is just
so icky and I don't quite trust the server behind the SBC to
understand what is going on. Ignoring a message is not an option
either and just flat out responding with a 4xx or 5xx also doesn't
feel quite right.

Will a newer OpenSIPS allow for an UPDATE message between 183 Session
Progress and the 200 OK for INVITE?

-- 
Andreas Sikkema