Re: [codec] #1: Application: 2.1. Point to point calls supporting transcoding?

Seems to me that there are two cases here - single gateway, and double
gateway.:In the double gateway case, Endpoint A connects to Endpoint B via a
gateway pair using PSTN.  The audio is converted to G.711 narrowband by the
first gateway, and back to the internet codec by the second.  The best
quality that can result is G.711, and the acoustic bandwidth is also limited
to narrowband, even though both endpoints can not see the G.711 hop.  Users
may have other expectations, but they cannot be met.

In any event, measuring the tandeming quality performance of this codec with
all other standard or popular) codecs would be a very tedious exercise, and
IMHO not practical.   We'd have to pick one or two codecs and let it go at
that.

Stephen Botzko

On Wed, Mar 24, 2010 at 1:59 PM, James Rafferty <James.Rafferty@dialogic.com
> wrote:

> Hi Christian,
>
> See below (JR).
>
> James
>
> -----Original Message-----
> From: Christian Hoene [mailto:hoene@uni-tuebingen.de]
> Sent: Wednesday, March 24, 2010 9:23 PM
> To: James Rafferty; codec@ietf.org
> Subject: RE: [codec] #1: Application: 2.1. Point to point calls supporting
> transcoding?
>
> Hi James,
>
> >-----Original Message-----
> >From: James Rafferty [mailto:James.Rafferty@dialogic.com]
> ...
> >Vendors of products on these network edges will take the steps needed to
> get endpoints to communicate
> >(as driven by their service provider customers), even if it requires a
> codec change to complete the
> >call.
>
> So, the main requirement in these cases is the interoperability.
> Conversational quality is of lesser importance.
> Thus, we need not particular quality requirements beside that it works OK?
>
> JR - An ability to interop is the first consideration and quality is still
> important; the customer will expect (whether reasonable or not) better than
> PSTN quality if wideband codecs are being used by both endpoints.
>
> Christian
>
> >
> >James
> >
> <snip>
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