[c-nsp] ASR9k Bundle QoS in 6.0.1

Saku Ytti saku at ytti.fi
Wed Jun 8 08:17:48 EDT 2016


On 8 June 2016 at 15:13, Adam Vitkovsky <Adam.Vitkovsky at gamma.co.uk> wrote:

> I think that most of this 10us budget is consumed on r/w from/to memories
> and then a tiny bit for lookup (if you are doing just pure IP lookup).
> If the fabric is meant to be non-blocking the arbitration(fabric routing)
> has to be negligible (buzz term: line-rate) that is within one tick of the
> fabric clock-rate the maximal solution has to be found and crossbar
> programed (I actually think the programing is done hand in hand with each
> found match) and data transmitted.

Let's assume this is true, that fabric query/grant is negligible part
of the overall budget. Then clearly LC can requery for grant if it
didn't receive it in X ns, and it will add negligible delay to overall
delay-through-chassis?
Giving us full redundancy over failover, without any between-fabric
intelligence or duplicate requests.

-- 
  ++ytti


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