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

Tue Sep 19 09:09:00 EDT 2006

This may seem silly but make sure that the actual files were not
recorded when the WAN was congested.  We had complaints one time from a
location of garbled greetings but it turned out that the recordings were
done during WAN congestion and just needed to be recorded again....

Carlos

________________________________

From: cisco-voip-bounces at puck.nether.net
[mailto:cisco-voip-bounces at puck.nether.net] On Behalf Of Kris Seraphine
Sent: Tuesday, September 19, 2006 12:37 AM
To: Wes Sisk
Cc: cisco-voip at puck.nether.net; STEVEN CASPER
Subject: Re: [cisco-voip] call quality issues between gateway and Unity

Just to update this issue, I found out that callers hear the system
prompts clear as a bell.  It's only the user greetings that are a
problem.  The users are recording their greetings over the WAN using
G.729 so it seems the gateway is having problems playing these out to
the PSTN user.  

I also noticed that the gateway seems to be hitting CSCsc12570 and calls
between it and Unity are not honoring the region settings.  I'm not sure
how all this fits together but hopefully an IOS upgrade will help. 

On 9/14/06, Wes Sisk <wsisk at cisco.com> wrote:

Steven,

No, this is not a blanket best practice recommendation.  It was a
workaround for the issue cited in that cdets.   If you have the time,
the best approach is to identify the cause of the robotic voice and 
modify the smallest possible set of options to address that issue.

/Wes

STEVEN CASPER wrote:
> Thanks Wes,
> This is very interesting. So is the recommendation to add "mgcp
playout
> adaptive 60 40 200" to all voice gateways that allow non IP phone
users 
> to access Unity? I have a lot of gateways that connect Nortel users to
> Unity via QSIG gateways. We occasionally get complaints of canned or
> robotic voice quality. We are running CCM 4.1.3sr1 with Unity 4.05.
>
> Steve
>
>>>> "Wes Sisk" <wsisk at cisco.com> 09/14/06 9:01 AM >>>
> Steven,
>
> Thank you for the clarification. Take a look at the Release-note of 
> the cited bug in bug toolkit.
>
> There is a different command to use with MGCP:
> mgcp playout adaptive 60 40 200
>
> Same underlying behavior, just modified for the call signaling
> protocol.
>
> /Wes
>
> On Sep 14, 2006, at 8:14 AM, STEVEN CASPER wrote:
>
> It is in the document Playout Delay Enhancements:
>
> http://www.cisco.com/en/US/products/sw/iosswrel/ps1834/
> products_feature_guide09186a008008033c.html
>
>
> in the link on Understanding Jitter that you posted.
>
> http://www.cisco.com/en/US/tech/tk652/tk698/
> technologies_tech_note09186a00800945df.shtml
>
>
> Steve
>
>>>> "Wes Sisk" <wsisk at cisco.com > 09/13/06 6:30 PM >>>
> 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
>>
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-- 
kris seraphine 

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