
As far as I know ISDN (call it Swissnet here, and it's being plugged in) it's
8 bit 8000Hz (gives you one channel of 64kBit/sec) I guess you should not go
below a sampling rate of 6000 Hz if you want to have same quality as on an
analog-line. Anybody knows compression-algorithms & -factors for voice ?

Greetings,

	Germano Caronni