Hi,
while debugging a mis-configured sip-phone we ran into this strange behavior of
the stack.
The phone sends an INVITE with two medias in its offer (audio & video):
m=audio 51788 RTP/AVP 0 3 8 101
m=video 57688 RTP/AVP 34
Instead of sending a 200 OK with a valid media description for the audio and a
mute or something like that for the video it does yet not supports, the stack
just send a 415 with no information about the failure that has occurred as
mandated by rfc.3261 (21.4.13 page 186).
Especially none of the mandatory headers (Accept, Accept-Encoding, or
Accept-Language) to be used in such a case are used.
Our quick hack was to add the Accept Header rfc.2616 (?14.1)
Accept: audio/*
in the response and the phone did show up afterwards with only one media in its
offer this time ;o)
But wouldn't it be better to just accept the call since PJSIP can handle the
audio stream ;o) and just set the port for the unsupported media to 0?
Cheers
Alain
INVITE sip:100001 at 192.168.001.100:5060 SIP/2.0
Record-Route: <sip:123.123.123.123;lr=on;ftag=as09234324>
Record-Route: <sip:234.234.234.234;lr=on>
Record-Route: <sip:123.123.123.123;lr=on;ftag=as09234324>
Via: SIP/2.0/UDP 123.123.123.123:5060;branch=z9hG4b2222.23456.9
Via: SIP/2.0/UDP 234.234.234.234;branch=z9hG4b2222.23456.9
Via: SIP/2.0/UDP 123.123.123.123:5060;received=217.10.68.226;branch=z9hG4b45c12345
Via: SIP/2.0/UDP 44.44.44.44:5060;branch=z9hG4b45c12345;rport=5060
From: "xyzFon" <sip:2000002@xxxxxxxxxx>;tag=as09234324
To: <sip:1234567 at foobar.xxx>
Contact: <sip:2000002 at 44.44.44.44:5060>
Call-ID: 2a6d8ddf684bf7718dd210f734eee at foobar.xxx
CSeq: 103 INVITE
Max-Forwards: 67
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY
Content-Type: application/sdp
Content-Length: 311
v=0
o=root 19999 20001 IN IP4 123.123.123.123
s=session
c=IN IP4 123.123.123.123
t=0 0
m=audio 51788 RTP/AVP 0 3 8 101
a=rtpmap:0 PCMU/8000
a=rtpmap:3 GSM/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-16
a=silenceSupp:off - - - -
m=video 57688 RTP/AVP 34
a=rtpmap:34 H263/90000
SIP/2.0 415 Unsupported Media Type
Via: SIP/2.0/UDP
123.123.123.123:5060;received=123.123.123.123;branch=z9hG4b2222.23456.9
Via: SIP/2.0/UDP 234.234.234.234;branch=z9hG4b2222.23456.9
Via: SIP/2.0/UDP 123.123.123.123:5060;received=217.10.68.226;branch=z9hG4b45c12345
Via: SIP/2.0/UDP 44.44.44.44:5060;rport=5060;branch=z9hG4b45c12345
Record-Route: <sip:123.123.123.123;lr;ftag=as09234324>
Record-Route: <sip:234.234.234.234;lr>
Record-Route: <sip:123.123.123.123;lr;ftag=as09234324>
Call-ID: 2a6d8ddf684bf7718dd210f734eee at foobar.xxx
From: "xyzFon" <sip:2000002@xxxxxxxxxx>;tag=as09234324
To: <sip:1234567 at foobar.xxx>;tag=8ca73284cf704cff8d6f09a50e520f8b
CSeq: 103 INVITE
Allow: PRACK, INVITE, ACK, BYE, CANCEL, UPDATE, SUBSCRIBE, NOTIFY, PUBLISH,
REFER, MESSAGE, OPTIONS
Supported: replaces, 100rel, norefersub
Content-Length: 0
--
""
(o)(o)
_____o00o__(__)__o00o_____
1024D/A9F85A52 2000-01-18 Alain Totouom <totouom at gmx.de>
PGP FingerPrint DA180DF2 FBD25F67 0656452D E3A27531 A9F85A52
