[cisco-voip] Strange behaviour of CME

[Nick Matthews]

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 ?
>> >
>> >
>> >
>> >
>>
>> _______________________________________________
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>> https://puck.nether.net/mailman/listinfo/cisco-voip
>>
>>
>
>
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