damn-it wrote:
>
> Any good alternative provider you can recommend?
>

It is nothing to do with voipfone.

And nothing to do with the Snom phone.

It is a deficiency in the SIP/RTP protocol.

Mute means one way audio. If the RTP sequence rolls over while you are
on mute, you lose the call.

I think. Could be other things too.

If you could get a pcap/ethereal trace of when the call drops out, I'd
know for sure.

Tim
(been to the pub, so I don't guarantee the above answer)