[asterisk-users] problem with T.38 media headers

[mario staphorst]

Hi Guys,

Something I have noticed while dealing with T.38 and re-invites in Asterisk 1.4.22.

I have a provider who re-invites with the following sdp (message flow
PROVIDER_EQPMT -> ASTERISK):

"""
.
v=0.
o=SIP_5F9 123456 654322 IN IP4 CONN_IP_PROVIDER.
s=-.
c=IN IP4 CONN_IP_PROVIDER.
t=0 0.
m=audio 0 RTP/AVP 0.
m=image 26858 udptl t38.
a=T38FaxMaxBuffer:288.
a=T38FaxRateManagement:transferredTCF.
a=T38FaxUdpEC:t38UDPRedundancy.
"""

The answer coming from asterisk in this case is:

"""
.
v=0.
o=root 3484 3485 IN IP4 CONN_IP_ASTERISK.
s=session.
c=IN IP4 CONN_IP_ASTERISK.
t=0 0.
m=image 4653 udptl t38.
a=T38FaxVersion:0.
a=T38MaxBitRate:9600.
a=T38FaxRateManagement:transferredTCF.
a=T38FaxMaxBuffer:200.
a=T38FaxMaxDatagram:200.
a=T38FaxUdpEC:t38UDPRedundancy.
"""

I see a problem here since the number of matched media streams from the
offer does not match with the number of matched media streams in reply
from asterisk (notice the m=audio 0 RTP/AVP 0 not present in the reply).

Please let me know if there are workarounds on this issue, or if this
could be a bug on asterisk side.
Best regards,
Mario Staphorst
_________________________________________________________________
Express yourself instantly with MSN Messenger! Download today it's FREE!
http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.digium.com/pipermail/asterisk-users/attachments/20090527/4e5373d5/attachment.htm