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Re: Internet Backbone Index
From: Stephen Balbach <stephen () clark net>
Date: Sun, 13 Jul 1997 20:15:48 -0400 (EDT)

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


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