[asterisk-users] Question on Codecs

[Manoj_Rajkarnikar]

On Thu, 17 Jul 2008, Nhadie wrote:

> Hi,
>
> I'm testing using the free g723 codecs and i have successfully installed
> them.
>          g723
>    g723     -
>     gsm     9
>    ulaw     9
>    alaw     9
>    g726     9
>   adpcm     9
>    slin     8
>   lpc10    10
>    g729    10
>   speex     -
>    ilbc    10
>
>
> i also set my pap2's to use G723. I'm sending the call to an AS5400 with
> multiple E1's on it. problem i noticed is that my CPU went up to 65%
> usage. From 4% when i was using ulaw. does asterisk still do codec
> translation even if the g723 codec is installed on it?
>
> this is the result from top command:
>                                           %CPU  %MEM
> 16829 asterisk  15   0 42500  22m 5520 S   65   2.6  91:21.93 asterisk
>
> i have 55 simultaneous users testing it. as far as my understanding,
> when g723 is installed on the asterisk there should be no codec
> translation done on the server thus not utilizing that much CPU.
> am i understanding it correctly? thanks in advanced

AFAIK, when asterisk switches calls from one format(i.e g723 etc) to other 
format(PCM), it needs to transcode the streams and that's what the codec 
that you installed are for. if both sides of the calls use same codec 
format, you wouldn't need any codec as asterisk would simply pass thru the 
streams. And I'm sure E1's won't use g723.

Manoj