UKVoIPTalk.com

Paul <nomailforme@polog40.org.uk> wrote in
news:457d2a89$0$624$5a6aecb4@news.aaisp.net.uk:
[color=blue]
> Pet @ [url]www.gymratz.co.uk[/url] ;¬) wrote:[color=green]
>> At a guess I presume inbound numbers from public PSTN routed from
>> ones VOIP supplier would be routed on the most economical codec eg
>> G712A/B[/color]
>
> Not in my experience, most stick to G.711a/u. It's still only needs
> about 80kbps per call which is fine for the vast majority of Internet
> connections these days. G729 would save on bandwidth but it's CPU
> intensive, this might not matter for you but it'll make a big
> difference for a service provider. It is also not a free codec and
> the license holder must be paid for it. I dare say that most
> importantly, it's lower quality than G711 (and therefore the PSTN) so
> the customer would perceive the service provider's service as poorer
> quality.
>[color=green]
>>
>> If that's the case, then if I were to force the voip ports to a
>> single codec e.g. G711MU, presumably the inbound call would be forced
>> to upscale to this single codec rather than the lowest it could get
>> away with?[/color]
>
> Yes if you set your VoIP hardware to only accept g711a/u then either
> the service providers server will agree to this or the call will fail.
>[color=green]
>>
>> Would there be any forseeable disadvantages doing this?
>> I see it as a way of getting max. call quality in inbound calls esp.
>> where downstream bandwidth is not such an issue as upstream.[/color]
>
> Less calls through your Internet connection. The calls require the
> same amount of bandwidth in either direction regardless of whether
> they are incoming calls or outgoing calls.
>[color=green]
>>
>> Any thoughts?
>> Pete[/color]
>[/color]

Most offer G.711a (this is the European/worldwide standard). It provides
the best 8khz sampled audio available.

G.711u is a US standard. G.726/729 or other compression standards (GSM,
Speex etc.) is only useful where bandwidth is a big issue.

peter