[cisco-voip] Changing codec to solve quality issue?

[Erick Wellnitz]

Not yet.  We are PRI for the time being.

It is phone to phone inter and intra site.  What it seems to me is that
there is something wrong with the the coding/decoding algorithm in these
8945s causing severe coder delay for g729.  The network is perfect and
there is more bandwidth than we could ever use for the PQ.


On Thu, Sep 19, 2013 at 10:05 PM, Justin Steinberg <jsteinberg at gmail.com>wrote:

> are you SIP trunk to the PSTN ?     I would assume poor audio on the g729
> codec could be caused within the carrier network.
>
>
> On Thu, Sep 19, 2013 at 2:03 PM, Erick Wellnitz <ewellnitzvoip at gmail.com>wrote:
>
>> Nothing appears out of the ordinary from the captures I've done on my
>> phone.  DSCP is set properly and there doesn't appear to be long delays in
>> packet delivery.
>>
>> One hypothesis we have is that the political aspect has amplified the
>> actual problem.
>>
>> I'll try to capture some more if I can convince someoen to switch back
>> for testing purposes.
>>
>>
>> On Thu, Sep 19, 2013 at 12:34 PM, Divin John (dijohn) <dijohn at cisco.com>wrote:
>>
>>> Do you have a packet capture from the Phone?
>>> Regards,
>>> Divin
>>>
>>> From: Erick Wellnitz <ewellnitzvoip at gmail.com>
>>> Date: Thursday, 19 September 2013 7:52 PM
>>> To: cisco-voip <cisco-voip at puck.nether.net>
>>> Subject: [cisco-voip] Changing codec to solve quality issue?
>>>
>>> CUCM 9.1.1a
>>> 8945 with sccp 9.3.2
>>>
>>> Really odd situation here.  If we use G.729 we have bad quality issues
>>> consistently even with QoS applied and confirmed by TAC.  If we use G.711
>>> we have no quality issues.
>>>
>>> We have plenty of bandwidth to run G711 but I don't like not knowing why
>>> something is happening.  It doesn't make sense why jitter and latency would
>>> be through the roof with G729 wile G711 is perfect.  I know G729 is more
>>> sensitive to latency and jitter but it shouldn't cause higher latency and
>>> jitter.
>>>
>>> Could this be something in the carrier's underlying architecture?
>>>
>>
>>
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>>
>>
>
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