[c-nsp] CEF and multicast on a 3750

[John Neiberger]

On Tue, Jun 26, 2012 at 9:02 AM, Phil Mayers <p.mayers at imperial.ac.uk> wrote:
> On 26/06/12 15:53, Gert Doering wrote:
>
>> Ahem.  "20 packets per seconds" is "constant", but can be bursty as well,
>> like "send 20 packets as fast as you can go, and then wait 0.99 seconds".
>
>
> Agree, vigorously.
>
> This is particularly common with video and audio streaming products, which
> seem to be universally developed on switches with 100Mb buffers, and fail
> catastrophically on devices with smaller buffers.
>
> 3750 and comparable switches from other vendors are particularly bad for
> this.

These are extremely expensive real-time video encoders taking in
baseband video and outputting multicast MPEG at a constant bit rate
for customer-facing video feeds. Any pauses would be unacceptable, as
are dropped packets, unfortunately for this site.  hehe

I'm engaging our Cisco team on this to have them investigate queueing
and buffer issues. I don't think they've looked at that yet.

Thanks!
John