[ltp] VOIP

[linux-thinkpad@linux-thinkpad.org]

> You may experience quality degradation calling "minor" markets where
> there is no PSTN gateway...for example when I call New Zealand, the
> closest gateway is Taiwan, and the call is then passed on to a cheap
> Taiwanese LD company who probably compresses the hell out of it and
> sends it to NZ...so I get up to a three second delay.

The main cause of degredation is not that the Taiwanese LD uses excessive compression as that the signal is getting at least 2 generations of compress-decompress-recompress.. each generation likely set at an "acceptable" quality, but add them together and you sound like you are underwater.

I've been hearing that a lot on radio/TV news lately with voice from remote correspondants in Iraq etc... pocket voice recorder played back through wireless (satellite?) phone, LD circuit, stored compressed on the network's computer.. THere's 4 generations.