Brian,

Enabling "Require SDP Inactive Exchange for Mid-Call Media Change" in the SIP 
profile of the CCM SIP trunk pointing at the CUSP server seems to have done the 
trick. No transcoding so far, and no call failures due to lack or transcoding 
resources.

This shouldn't be needed for supplementary service midcall INVITES on 79XX 
endpoints if I'm understanding that feature correctly, yes?

-ryan
Date: Thu, 7 May 2015 20:21:18 -0400
Subject: Re: [cisco-voip] Codec negotiation issue, a little strange
From: [email protected]
To: [email protected]
CC: [email protected]

That may help but it's probably easier to just start with the "debug ccsip 
messages" to see what the router is sending in the outgoing Invite to CUSP.
On Thu, May 7, 2015 at 7:50 PM, Ryan Huff <[email protected]> wrote:
Brian,
I'm guessing that the router in this case is somehow, messing with the codec.
Since the regions are g722/g711 that means g729 would be allowed in the region 
because it fits the bandwidth profile of the region.
Do you think doing a "pass-thru content unsupp" would be helpful in either 
eliminating or proving the router as the source of the issue?
As I understand it, this should allow sdp to pass to the other call leg without 
media negotiations.
Thanks,
Ryan


-------- Original Message --------
From: Brian Meade <[email protected]>
Sent: Wednesday, May 6, 2015 05:54 PM
To: Ryan Huff <[email protected]>
Subject: Re: [cisco-voip] Codec negotiation issue, a little strange
CC: [email protected]

CVP doesn't change SDP info and CUSP might not either, don't remember.  Can you 
run "debug ccsip messages" on the H.323 GW to see if it's offering anything 
other than G.711ulaw in the Invite to CUSP?  If it's only G.711 there, it must 
be getting changed by CUSP.  I'm not familiar enough with it to know what to 
check though.
On Wed, May 6, 2015 at 5:40 PM, Ryan Huff <[email protected]> wrote:



I have a situation, where, in some case the ingress pstn call leg is trying to 
use g.729 (when there is nothing in the gateway that would indicate it's 
preference).

Call path when G729 is negotiated:

PSTN -> h.323(PRI) 
dial-peer match -> SIP trunk to Unified Proxy Server - > SIP 
Customer Voice Portal -> SIP To vXML Server -> Send SIP invite to 
call manager and the SDP contains G729

Call path when G711 is negotiated:

PSTN - >h .323(PRI) dial-peer match -> CCM -> ring phone

- The gateway and IP phone are in the same region and the region is related to 
itself with G711.
- The region of the DP of the SIP trunk is related to the region of the gateway 
and the region of the phone with G711
- The voice class codec on the router only has g711 set as the 1st preference
- The matched dial-peer (h.323) for the SIP trunk to CUSP is specifying the 
voice class codec correctly
- The IP phone is a 7962/42

My question is how and why is the far end negotiating G729? This site does have 
limited CIR (10 Mbps) and the CVP/vXML servers are in a different geographic 
location than the gateway/IP phone.

My thought is that since the IP phone can negotiate G.729, it could be a 
bandwidth thing where it is just choosing to use the lower bandwidth codec BUT 
the invite to CCM is coming from CVP. The SDP in the invite shows G729.

Content-Type: application/sdp
App-Info: <vXMLVoiceServerIPAddress:8000:8443>
v=0
o=CiscoSystemsSIP-GW-UserAgent 7410 5486 IN IP4 GatewayIpAddress
s=SIP Call
c=IN IP4 GatewayIpAddress
t=0 0
m=audio 19808 RTP/AVP 0 18 100 101
c=IN IP4 GatewayIpAddress
a=rtpmap:0 PCMU/8000
a=rtpmap:18 G729/8000
a=fmtp:18 annexb=yes
a=rtpmap:100 X-NSE/8000
a=fmtp:100 192-194
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-16


                                          

_______________________________________________

cisco-voip mailing list

[email protected]

https://puck.nether.net/mailman/listinfo/cisco-voip





                                          
_______________________________________________
cisco-voip mailing list
[email protected]
https://puck.nether.net/mailman/listinfo/cisco-voip

Reply via email to