[trotsky]

yeah, its so low. im not sure what skype uses for a codec on pstn interconnects but it's probably better than most given that its easy to upgrade a closed ecosystem. Speex vbr at 16 is probably pretty middle of the road for voip, it doesn't sound that great but people put up with worse. leaving room for overhead and jitter still puts you over 5000 concurrent 16kbit channels, and id be surprised if they saw more than a few percent of their outbound customers active at any given time. standards based equipment is super cheap too as the protocols and such were designed to be managed by embedded systems.