[10762] in North American Network Operators' Group
Re: Internet Backbone Index
daemon@ATHENA.MIT.EDU (Stephen Balbach)
Sun Jul 13 20:29:09 1997
Date: Sun, 13 Jul 1997 20:15:48 -0400 (EDT)
From: Stephen Balbach <stephen@clark.net>
To: "Dorian R. Kim" <dorian@blackrose.org>
cc: nanog@merit.edu
In-Reply-To: <Pine.GSO.3.96.970713194600.21848P-100000@thorn.blackrose.org>
On Sun, 13 Jul 1997, Dorian R. Kim wrote:
> On Sun, 13 Jul 1997, Stephen Balbach wrote:
>
> > On Sun, 13 Jul 1997, Randy Bush wrote:
> >
> > > There is one significant difference between routed and switched backbones.
> >
> > Doesnt an IP Switch have lower latency and higher pps?
>
> What's an IP switch? If you can define what this is other than a marketing
> stunt, I'd appreciate it.
Routes the first packets and switches the rest based on "flows". It
is not dependent on layer 2 or PVC's to determain the correct
route? This is what Ive read from the mfg's who claim higher pps via this
method then straight routing.
I realize this is similair to the C vs C++ argument - C++ is a method
more then a language, IP Switcing is more a routing technique then a
new hardware technology. But is it worth it?
> > Is a Cisco running NetFlow any faster then a routed Cisco?
>
> No. A cisco router running netflow switching doesn't make it a switch, just as
> a cisco router running optimum switching doesn't make it a switch either.
>
> There can be large amounts of confusion that gets created because of marketing
> silliness.
>
> All routers and switches forward traffic. When the forwarding decision is
> made in layer 3, this is usually referred to as being "routed" and when
> forwarding decision is made in layer 2, this is usually referred to as
> being "switched".
>
> People also refer to hardware/interface/link layer level forwarding decisions
> made in routers as "switching."
>
> Hence, "fast" switching, "optimum" switching, and "netflow" switching in cisco
> term, which doesn't make a router a switch.
>
> Most routers have the capability of being switches, while most switches don't
> have the capability of being routers. (routers by their function needs to talk
> to layer 2, while switches do not necessarily have to)
>
> Since people seem to think that switch has some magically theraputic quality
> to network performance I wonder why Bay marketing hasn't started making a big
> deal about the fact that their BCNs function as frame relay switches.
I assume at some level it makes sense to do switching for topology
reasons. But for performance, it is not a benefit?
.stb
