[OpenSIPS-Users] codec manipulation feature

[Jeff Pyle]

Hi Bogdan,

It¹s been a little while since we talked about this.  I was wondering if
there was anything in the works to detect and/or manipulate the codecs
present in an SDP.



- Jeff



On 2/1/09 4:08 AM, "Steve Kurzeja" <steve.kurzeja at gmail.com> wrote:

> This idea is quite standard in SBCs, typically called codec profiles, where
> you permit only certain codecs to be passed through the SBC in an INVITE and
> all the rest are stripped out.
> 
> We use it to get around interop issues with certain codecs. E.g. we have some
> end devices/customers that have issues using g729a so we choose to remove this
> codec for these specific endpoints.
> 
> The poor man's method to implementing this is just doing header manipulations
> in the SDP but it would be nice to be standardized.
> 
> Regards,
> Steve
> 
> 
> On Fri, Jan 30, 2009 at 2:20 AM, Jeff Pyle <jpyle at fidelityvoice.com> wrote:
>> Hi Bogdan,
>> 
>> I'm looking for the ability to selectively remove codec advertisements from
>> the SDP.  For example, if my customer sends a call to me for PSTN
>> termination he may advertise G711 and G729, with G711 preferred.  By looking
>> at the number of existing dialogs I may know that he's running low on
>> bandwidth, so I would like to suppress the G711 advertisement ultimately
>> causing a 200 OK from the carrier with G729.
>> 
>> Generically, in this application we're looking only to suppress G711 at
>> certain times.
>> 
>> I understand normally codec selection is done completely by the gateway
>> device.  However, my gateway devices aren't smart enough to take bandwidth
>> utilization into consideration when choosing which codecs to advertise.  I'm
>> hoping my proxy might be.  :)
>> 
>> Does that make sense?
>> 
>> 
>> 
>> - Jeff
>> 
>> 
>> 
>> On 1/29/09 5:04 AM, "Bogdan-Andrei Iancu" <bogdan at voice-system.ro> wrote:
>> 
>>> > Hi Jeff,
>>> >
>>> > right now there is only available some functionality to check the codecs
>>> > (to see what codecs are advertised in the SDP)... What exactly are you
>>> > looking for (like codec ops) ?
>>> >
>>> > Regards,
>>> > Bogdan
>>> >
>>> > Jeff Pyle wrote:
>>>> >> Bogdan,
>>>> >>
>>>> >> Some months back you mentioned an upcoming feature that would allow
>>>> >> Opensips to manipulate the codecs present in the SDP.  Just wondering
>>>> >> if there is anything available to test yet.  This feature, in
>>>> >> combination with dialog contexts, will be of great use to us to allow
>>>> >> us to take a guess at the bandwidth consumption for a particular
>>>> >> customer and force the use of a compressed codec if necessary.
>>>> >>
>>>> >>
>>>> >> Thanks,
>>>> >> Jeff
>>> >
>> 
>> 
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> 
> 

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