[Asterisk-Users] Codecs and bandwidth

[Tim Pushor]

Hi Friends,

Something I'd like to shed some light on if possible - how is it that a 
single ISDN conversation only uses 64K for bidirectional communication 
(using ulaw, correct?), but on several occasions now have seen 
references to ulaw voip conversations using 64K per side of the 
conversation, plus packet overhead 
(http://www.zytrax.com/tech/protocols/voip_rates.htm - seems to be down 
now - plus other references) for a total of over 128K per ulaw 'full 
duplex' voice conversation?

Thanks
Tim