Voice delay (beginner question)

Hi

I use Voipfone and FWD mainly for my voice calls. If I call someone
in the UK (I live in the UK) using Voipfone all is well. If I use fwd
to call someone in the UK there is a very slight delay. This can be
demonstrated using a UK echo test with both Voipfone and FWD.

My question is, why should there be a sound delay using a US service.
I understood that whilst the call set-up is in the US the actual call
is peer-to-peer?

Feel free to get as technical as you like!

Thanks.

Chris

On 4 Mar 2007 04:25:16 -0800, chrisips2@gmail.com wrote:

>Hi
>
>I use Voipfone and FWD mainly for my voice calls. If I call someone
>in the UK (I live in the UK) using Voipfone all is well. If I use fwd
>to call someone in the UK there is a very slight delay. This can be
>demonstrated using a UK echo test with both Voipfone and FWD.
>
>My question is, why should there be a sound delay using a US service.
>I understood that whilst the call set-up is in the US the actual call
>is peer-to-peer?
>
>Feel free to get as technical as you like!
>
>Thanks.
>
>Chris
No matter how it is routed the longer the link the more delay you get.
Check out www.speedtest.net to find out the delay to various servers
thoughout the world. There you can check out the latency. Just drag
the map to get to places currently off screen.

Remove 'no_spam_' from email address.

On 4 Mar, 12:54, Brian A <no_spam_bca1...@hotmail.com> wrote:
> On 4 Mar 2007 04:25:16 -0800, chrisi...@gmail.com wrote:
>
>
>
> >Hi
>
> >I use Voipfone and FWD mainly for my voice calls. If I call someone
> >in the UK (I live in the UK) using Voipfone all is well. If I use fwd
> >to call someone in the UK there is a very slight delay. This can be
> >demonstrated using a UK echo test with both Voipfone and FWD.
>
> >My question is, why should there be a sound delay using a US service.
> >I understood that whilst the call set-up is in the US the actual call
> >is peer-to-peer?
>
> >Feel free to get as technical as you like!
>
> >Thanks.
>
> >Chris
>
> No matter how it is routed the longer the link the more delay you get.
> Check outwww.speedtest.netto find out the delay to various servers
> thoughout the world. There you can check out the latency. Just drag
> the map to get to places currently off screen.
>
> Remove 'no_spam_' from email address.
Thank you for your reply. I suppose what I was asking is that, the
actual call is surely peer-to-peer, so once the call is setup, the
voice packets of data don't actually get routed through FWD. Surely
the packets of voice data go straight to the other party?

If the packets of voice data went via FWD then I would expect the
service to be costly to run (due to the amount of data moving around
the providers network) and more lost packets (due to the way in which
intermediate networks handle the UDP data).

Is there any good resource that I can go to learn all about how the
calls are set-up, transferred and what actually happens during the
call. I am working on VOIP for a university degree course and it
would be great if someone had some pointers on where I can go to learn
the intrecacies of SIP and VOIP technology.

Many thanks.

Chris

chrisips2@gmail.com wrote:
> My question is, why should there be a sound delay using a US service.
> I understood that whilst the call set-up is in the US the actual call
> is peer-to-peer?

I'm guessing that one end or the other is behind a NAT.

Therefore, the RTP (audio data) is probably being relayed by an FWD
service in the states.

The RTP would be peer to peer if you were both on public IP addresses
(not behind a NAT).

If you had a Snom phone, you could look at the SIP trace of the call to
see what is going on.

Tim

chrisips2@gmail.com wrote:
> Hi

> I use Voipfone and FWD mainly for my voice calls. If I call someone
> in the UK (I live in the UK) using Voipfone all is well. If I use fwd
> to call someone in the UK there is a very slight delay. This can be
> demonstrated using a UK echo test with both Voipfone and FWD.

> My question is, why should there be a sound delay using a US service.
> I understood that whilst the call set-up is in the US the actual call
> is peer-to-peer?

Not if you have it setup to use their "Outbound Proxy" and it's
proxying the audio stream through there. It also adds a lot of
unreliability to the setup too from my experience (their audio proxy
goes down a lot it seems).

In message <1173027156.914235.117330@30g2000cwc.googlegroups. com>,
chrisips2@gmail.com writes
>
>Is there any good resource that I can go to learn all about how the
>calls are set-up, transferred and what actually happens during the
>call. I am working on VOIP for a university degree course and it
>would be great if someone had some pointers on where I can go to learn
>the intrecacies of SIP and VOIP technology.
>

http://www.eventhelix.com/RealtimeMantra/Telecom/

--
Ian