[cisco-voip] call quality issues between gateway and Unity

[Wes Sisk]

Steven,

Where do you get that playout-delay is not supported?

/Wes

STEVEN CASPER wrote:
> Wes,
> I see that Playout-Delay is not supported on MGCP platforms so how is
> jitter handled in a MGCP/Call Manager enviroment?
> 
> Thanks!
> Steve
> 
> Steve Casper
> Voice Technologies
> M&T Bank
> (410) 347-6026
> 
>>>> "Wes Sisk" <wsisk at cisco.com> 09/11/06 7:00 PM >>>
> Kris,
> 
> This sounds very similar to something we fixed long ago.  Take a look 
> 
> at 'sh voice call' to see if it's jitter:
> http://www.cisco.com/en/US/tech/tk652/tk698/ 
> technologies_tech_note09186a00800945df.shtml
> 
> CSCea35850 - Unity RTP stream has inherent jitter
> 
> 
> If you are using non-default packetization periods watch out for
> CSCed52913 Unity RTP stream has jitter with G.729 at 30 & 60 ms and  
> G711/30ms
> 
> /Wes
> 
> On Sep 11, 2006, at 5:56 PM, Kris Seraphine wrote:
> 
> Hi
> 
> I have a customer with a multi site centralized CCM 4.13 cluster.   
> The remote sites are getting complaints of poor voice quality from  
> customers when being transferred to Unity (which is located in the  
> central site) .  The callers cannot understand the greetings and  
> describe them as choppy.  There are no problems with external calls  
> transferred from the remote sites to IP phones at the central site or 
> 
> for intersite calls.  It seems to be limited to calls where the RTP  
> stream is between a remote voice gateway and Unity.  These calls are  
> G.729 so Unity has to transcode the greetings on the fly but if that  
> were the problem I'd expect remote users to have the same problem  
> when calling into check their messages or leave messages for other  
> users.  Also, the Unity server is not very heavily used; it generally 
> 
> has no more than 9 active calls at the most.
> 
> I suspect the gateway might be the problem.  It's a 2851 running  
> MGCP.  I guess I'd like to know if anyone agrees or disagrees with  
> this assumption.  Also, I've had a lot of problems with MGCP code on  
> the ISRs.  Can someone recommend an IOS version that is stable for  
> and MGCP gateway and doesn't suffer from DSP firmware issues?
> 
> I should mention that Unity is version 4.04 sr1 and the gateway is  
> running 12.4(5).
> 
> Thanks
>