Re: [nsp] VOIP Over ATM 7200VXR's ?

From: Stephen Sprunk (ssprunk@cisco.com)
Date: Mon Oct 15 2001 - 19:20:50 EDT


Thus spake "Kevin Gannon" <kgannon@lancomms.ie>
> We are looking at running VOIP over some ATM PVCs the problem I think
> we are going to run into is queueing. The 7200VXRs do not seem to
> support WFQ at the PVC rates we run (90Mps).

WFQ is not supported for any link speed over 2Mbps due to CPU/memory
constraints.

> Questions:
> 1. With FIFO do you get a seperate set of queues for each
sub-interfaces,
> so if we ran up a seperate PVC/Interface then we could live with FIFO
on
> just this interface.

That's the default anyways. You'd be better off with WRED than FIFO,
though.

> 2. Do the newer queueing features LLQ/CBWFQ support higher data
> rates ?

LLQ over ATM subinterfaces is supported in 12.1T and later. Be sure to
use WRED in the class-default otherwise the default WFQ will kill your
CPU.

> 3. Is anyone brave enough to run VOIP with FIFO ?

Not anyone who likes clear audio.

> 4. We are even willing to run with a TDM/CES solution and buy nailed
up
> bandwidth but there is only a full length CES card which means
getting
> rid of the existing ATM PA's :o(.

Yuck. CES is evil.

> Regards,
> Kevin

S



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