25 เมษายน 2550 13:51
I'm getting this error in the event log from MSS:
Application Error 50000: An exception occurred in the Speech workflow with Id cec8ce2e-07c1-4a25-ab07-cfbae8f9b468. The exception was: An invalid media description was received from the remote end.
Here's the SDP from the INVITE coming from MSS:
o=- 0 0 IN IP4 10.0.0.29
s=Microsoft Speech Server session
c=IN IP4 10.0.0.29
m=audio 38400 RTP/AVP 114 115 4 0 8 101
And here's the SDP in the OK from my gateway:
o=8888888 8000 8000 IN IP4 10.0.0.40
c=IN IP4 10.0.0.40
m=audio 5004 RTP/AVP 4
4 is Media Format: ITU-T G.723, and it is listed as one of the formats in the initial INVITE.
Why doesn't this work?
26 เมษายน 2550 11:59
Ok, we figured this one out.
We're using a Grandstream SIP phone and an ht488 gateway for testing, and we had to make this change to the config screen:
Send DTMF: in-audio via RTP (RFC2833) via SIP INFO
Originally it was set to "in-audio".
This adds a 101 to the media description line in the SDP, and also Media Attribute (a): fmtp:101 0-11