[VoIP] Cable questions

[Rusty Dekema]

> This typically only applies to the link from the DSLAM in the CO to the DSL modem at your end.  Out of the DSLAM, there is a shared IP uplink to where ever the provider aggregates traffic to the Internet.  This is the same basic architecture as the CMTS at the cable headend to your cable modem (although you are right that timeslots are shared between subscribers in the cable modem ) In my experience, the providers  have the most expense and therefore the lowest incentive to ensure that the uplinks are  properly sized.

That is definitely true but in my experience, I've always seen more
jitter when connecting to the Internet via a cable network than a DSL
line, even when the cable network in question otherwise seems to work
well (in terms of throughput and latency).

Excessive jitter really screws up VoIP connections; you either get a
lot of audio glitches due to missing/mistimed packets or you have to
increase the size of your jitter buffer to something quite large,
resulting in excessive mouth to ear latency.

Rusty