[sip-comm-dev] Session setup with no media


Hi to all our SIP gurus,

yet another nice report :slight_smile: .

MS and I tried to setup some test call. Due to some mistake
MS disabled the microphone and other audio stuff. This
lead to some unexpected results (see attached wireshark
trace). Also have a look at the attached text file that
reports some ugly problems. Please note that both clients
are SC. MS uses a fairly new build (2146). My SC was build
from SVN sources matching build 2150.

All line numbers refer to the wireshark file:

First case:
Line 21: INVITE, MS tries to invite my SC. Look at the
         SDP data: no media data at all
Line 26: RINGING, I would suspect a 488 not acceptable here
         because of missing media?
Line 31: 200 OK, my SC aresponds with OK and full media
Line 32: ACK, MS sends an ACK??? At least here I would have
         suspected a 488
Line 46: BYE, after some time I decided to hangup, my SC sends
         a BYE but somehow no ACK from MS to the BYE so SC
         repeats this.

Second case:
Line 658: INVITE, I invite MS, sending full media information
Line 671: RINGING
Line 803: 488, Here MS's SC sends the right response because it
          does not find a match.

For the first case I would have expected a similar behaviour.

In the first case SC receives an empty set of media data in INVITE
and answers with a full set of media data in OK. And the caller
that receives the OK with the full set does not send a 488 but
an ACK.

To analyse these problems the text file may give some additional
info. It shows some errors for dialog termination etc.

Another problem: iptel.org sends quite a lot of SIP SUBSCRIBE
messages, my SC fails to respond. See text file for the error
messages regarding NOTIFY

Yet another issue or two?

Have fun.

Best regards,

NoMedia.pcap.gz (23.9 KB)

NoMedia.txt.gz (2.69 KB)