[183138] in North American Network Operators' Group
Re: Drops in Core
daemon@ATHENA.MIT.EDU (William Herrin)
Sat Aug 15 13:17:25 2015
X-Original-To: nanog@nanog.org
X-Really-To: <nanog@nanog.org>
In-Reply-To: <CAPLq3UNDsmXwooDjY7RaGJa8SqQ1b-PsO7V8W8W3ujs2LmgKsg@mail.gmail.com>
From: William Herrin <bill@herrin.us>
Date: Sat, 15 Aug 2015 13:16:51 -0400
To: Glen Kent <glen.kent@gmail.com>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
On Sat, Aug 15, 2015 at 1:07 PM, Glen Kent <glen.kent@gmail.com> wrote:
> Youre saying that the probability of packet drop at peering points would
> roughly match that at the edge. Is it? I thought that most core switches
> have minimal buffering and really do cut-through forwarding. The idea is
> that the traffic that they receive is already shaped by the upstream
> routers.
Hi Glen,
It a capacity question. Several core networks [cough Verizon cough]
intentionally under-provision the "settlement-free" peering links to
other core networks. You can't cut-through when the destination
interface already has a queue of packets waiting to be sent.
Regards,
Bill Herrin
--
William Herrin ................ herrin@dirtside.com bill@herrin.us
Owner, Dirtside Systems ......... Web: <http://www.dirtside.com/>
