[cisco-voip] Unity External Transcoding

Thu Apr 6 15:07:31 EDT 2006

I've been watching this conversation since it started and have a
question.
I'm trying to figure out how to disable Unity from using g.729.
I thought this would be configured using the advanced settings tool but
I can't find it in there.
Can anyone point me to a resource on cisco.com for this.

Thanks
Scott

-----Original Message-----
From: cisco-voip-bounces at puck.nether.net
[mailto:cisco-voip-bounces at puck.nether.net] On Behalf Of Pritchard, Jon
Sent: Tuesday, March 28, 2006 2:28 PM
To: Ryan Ratliff
Cc: Voll, Scott; cisco-voip at puck.nether.net
Subject: Re: [cisco-voip] Unity External Transcoding

Goal is to support G729 for voice mail and AA for remote sites and G711
for the host site.  We want to offload the transcoding to external
hardware to improve voice quality by not relying on the Unity server CPU
performance.

With native transcoding enabled on Unity (no G729 registry entry) which
supports both G729 and G711 streams from Unity then we found during busy
times of the day (this configuration has 24x7 auto-attendant for five
sites of main numbers) the voice quality degrades as the CPU utilization
goes up.

Jon

-----Original Message-----
From: Ryan Ratliff [mailto:rratliff at cisco.com]
Sent: Tuesday, March 28, 2006 11:20 AM
To: Pritchard, Jon
Cc: Voll, Scott; cisco-voip at puck.nether.net
Subject: Re: [cisco-voip] Unity External Transcoding

Was your goal to get Unity using only g.711 or both g.711 and g.729?

-Ryan

On Mar 28, 2006, at 2:16 PM, Pritchard, Jon wrote:

You might be on to something.  Unity VM ports and the transcoder are in
the same device pool/region.  However, one of the tests was to force the
in-region codec to G729 so that even connections from local phones in
the same device pool/region (i.e. host site phones) so everything was
G729.  I'm 99% sure this worked.

I'll recheck/retest after hours tonight.

Jon

-----Original Message-----
From: Ryan Ratliff [mailto:rratliff at cisco.com]
Sent: Tuesday, March 28, 2006 11:10 AM
To: Pritchard, Jon
Cc: Voll, Scott; cisco-voip at puck.nether.net
Subject: Re: [cisco-voip] Unity External Transcoding

  From your description I don't see why an MTP would be required at all.

If you have disabled g.729 on your Unity ports then for a call between
Unity and a g.729 region Unity should talk g.711 to the transcoder and
the transcoder should talk g.729 to the other
endpoint.   I'd check the region config between your voicemail ports
and the transcoder.  If that is set to g.729 then the call will fail.

-Ryan

On Mar 28, 2006, at 1:55 PM, Pritchard, Jon wrote:

MTP in general isn't required.  It's for things like non-Cisco devices
(i.e. H323 phones) which don't have the ability to terminate the RTP
stream themselves.

The big question is why is MTP coming into play here (there's nothing
I've found on CCO to support this requirement).

Even if MTP is required here why is the MediaControlPoint looking for
resource on the GW that isn't defined let alone in any MRG/MRGL.

All I can think to do is to reconfigure the DSP farm for MTP, add it to
CCM and the MRG/MRGL's and see what, if any, difference it makes.

Jon

-----Original Message-----
From: Ryan Ratliff [mailto:rratliff at cisco.com]
Sent: Tuesday, March 28, 2006 10:44 AM
To: Pritchard, Jon
Cc: Voll, Scott; cisco-voip at puck.nether.net
Subject: Re: [cisco-voip] Unity External Transcoding

CallManager only as in software MTP?  That isn't a transcoder it's a
g.711 only MTP.

-Ryan

On Mar 28, 2006, at 1:31 PM, Pritchard, Jon wrote:

The MTP resource is CallManager only at this point and it's in the
MRG/MRGL for all devices.

Jon

-----Original Message-----
From: Voll, Scott [mailto:Scott.Voll at wesd.org]
Sent: Tuesday, March 28, 2006 8:38 AM
To: Pritchard, Jon; cisco-voip at puck.nether.net
Subject: RE: [cisco-voip] Unity External Transcoding

Have you double checked the GW includes the Media Resource group that
has the MTP in it?

-----Original Message-----
From: cisco-voip-bounces at puck.nether.net [mailto:cisco-voip-
bounces at puck.nether.net] On Behalf Of Pritchard, Jon
Sent: Tuesday, March 28, 2006 7:49 AM
To: cisco-voip at puck.nether.net
Subject: [cisco-voip] Unity External Transcoding

I'm attempting to enable Unity external transcoding for g729 connections
to offload CPU and improve voice quality.  I have a PVDM2 based DSPFarm
with 80 transcoder sessions.  I have successfully disabled native
transcoding on Unity and have verified external transcoding is in play
when calling Unity internally (VM or AA) from
a Region set for g729 relative to the Region Unity is in.   However,
when external calls are routed to Unity from the g729 regions I get
disconnected with what "sounds" like a codec mismatch.

I compared the CCM traces (detailed/debug) of the successful internal
calls vs. the failed external calls.  The successful calls showed the
MediaResourceManager negotiating the transcoder connection and minimal
MediaTerminatePointControl activity.  The unsuccessful calls didn't show
a specific error but does show trying to push a G711ulaw payload during
the MediaTerminationPointControl phase and no interaction with the
MediaResourceManager to set up transcoding.

The gateways involved are 1760 H323 on 12.3(8)T4 and have both G711 and
G729 codecs enabled via codec class in the dial-peers, pref 1
G711 and pref 2. G729.

The really weird part is the external connections have been and still
are successful when Unity is running native transcoding with the rest of
the configuration is the same.

Is it possible I'm missing something relative to MTP requirements?
MTP resource is currently limited CallManagers and is within scope of
the MRGL for all devices, VM ports and gateways included.

Any insight you might have would be appreciated.

Thx,
Jon Pritchard

This message and any attachments are intended only for the use of the
addressee and may contain information that is privileged and
confidential. If the reader of the message is not the intended recipient
or an authorized representative of the intended recipient, you are
hereby notified that any dissemination of this communication is strictly
prohibited. If you have received this communication in error, please
notify us immediately by e-mail and delete the message and any
attachments from your system.

_______________________________________________
cisco-voip mailing list
cisco-voip at puck.nether.net
https://puck.nether.net/mailman/listinfo/cisco-voip

This message and any attachments are intended only for the use of the
addressee and may contain information that is privileged and
confidential. If the reader of the message is not the intended recipient
or an authorized representative of the intended recipient, you are
hereby notified that any dissemination of this communication is strictly
prohibited. If you have received this communication in error, please
notify us immediately by e-mail and delete the message and any
attachments from your system.

_______________________________________________
cisco-voip mailing list
cisco-voip at puck.nether.net
https://puck.nether.net/mailman/listinfo/cisco-voip

This message and any attachments are intended only for the use of the
addressee and may contain information that is privileged and
confidential. If the reader of the message is not the intended recipient
or an authorized representative of the intended recipient, you are
hereby notified that any dissemination of this communication is strictly
prohibited. If you have received this communication in error, please
notify us immediately by e-mail and delete the message and any
attachments from your system.

_______________________________________________
cisco-voip mailing list
cisco-voip at puck.nether.net
https://puck.nether.net/mailman/listinfo/cisco-voip