[cisco-voip] Strange behaviour of CME
Cisco Voip
cisco_newbie at yahoo.com
Wed Jan 26 00:54:31 EST 2011
Dear Sir,
So i am right in my concept (cleared by you :-)) that transcoding didnt happen
because IPC support g729 codec ??
Please confirm it
________________________________
From: Nick Matthews <matthnick at gmail.com>
To: Cisco Voip <cisco_newbie at yahoo.com>
Cc: ccieid1ot <ccieid1ot at gmail.com>; cisco-voip at puck.nether.net
Sent: Wed, January 26, 2011 10:32:29 AM
Subject: Re: [cisco-voip] Strange behaviour of CME
The phone supports multiple codecs. They simply have different priorities. The
reason you always see g711 instead of g729 is because g711 has a higher
priority. The modern phones (7942/7962 and above) support something like 7+
codecs.
-nick
On Tue, Jan 25, 2011 at 11:37 PM, Cisco Voip <cisco_newbie at yahoo.com> wrote:
Dear Sir,
>
>As a followup, by default SCCP phones use codec g711. So did you mean that
>phones automatically switched to g729 ? i totally believe your point but for my
>further studies can you also refer me any cisco config guide to strengthen my
>concept
>
>
>Pls verify my above point
>
>
>
>
________________________________
From: Nick Matthews <matthnick at gmail.com>
>To: ccieid1ot <ccieid1ot at gmail.com>
>Cc: Cisco Voip <cisco_newbie at yahoo.com>; cisco-voip at puck.nether.net
>Sent: Wed, January 26, 2011 5:10:12 AM
>Subject: Re: [cisco-voip] Strange behaviour of CME
>
>
>Transcoding is only required when there is a codec mismatch. In this case it's
>something like:
>
>Phone 1:
>g711ulaw
>g711alaw
>g729r8
>g729br8
>g722
>...
>etc
>
>GW1 to GW2:
>g729r8
>
>Phone 2:
>same as above phone 1
>
>
>Since g729r8 is available by all, there is no need for transcoding.
>
>-nick
>
>
>On Tue, Jan 25, 2011 at 2:47 PM, ccieid1ot <ccieid1ot at gmail.com> wrote:
>
>The phones has built in dsp to do the transcoding.
>>duy
>>ccie #27737 voice
>>tmobile g2
>>On Jan 25, 2011 10:03 AM, "Cisco Voip" <cisco_newbie at yahoo.com> wrote:
>>> Hi all.
>>>
>>> I have setup the current setup in my lab
>>>
>>> IPcommunicator-1
>>> ------------------R1-GW-------------------R2-GW-------------IPcommunicator-2
>>>
>>> SCCP (g711) default (g729)
>>>
>>> On R1 i simply created a dial-peer voice 2141 voip, and defined the session
>>> target and destination pattern, and also codec to be g729r8. Now when i call
>>> from IPc-1 to IPc-2, the call is successful !!
>>>
>>> I have set this up in dynamips and 2 IPcs are infact vmware machines. What i
>>> dont understand is, why there was no need for transcoding ? the default codec
>
>>> between R1-GW and IPc-1 is g711, while between R1-GW and R2-GW, i set it to
>>> g729, so isnt transcoding needed here ?
>>>
>>>
>>>
>>>
>>
>>_______________________________________________
>>cisco-voip mailing list
>>cisco-voip at puck.nether.net
>>https://puck.nether.net/mailman/listinfo/cisco-voip
>>
>>
>
>
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