Subject: RE: [bmwg] RE: Wire speed definition

From: Scott Bradner <[email-masked]>
Date: Mon, 22 Jan 2001 10:28:15 -0500 (EST)

that is fine but routers do not work in bits they work in packets

it is also quite a different load on a router to do minimum vs maximum
sized frames - many routers that can deal with filling a wire (in 
bps) at 1500 byte frames can not do so at 64 byte frames

so what I was addressing is creating a definition for bmwg testing 
for "line rate" that deals with the type of packet-based testing 

Scott

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From: Scott Poretsky <[email-masked]>
Date: Mon, 22 Jan 2001 10:56:30 -0500

Scott B,

It is true Routers work in packets.  Optical switches work in 
bits.  Suppose I have to validate interoperability performance of  a router 
and an optical switch for GMPLS.  The question is does my OC-192c link 
really achieve 10Gbps.  If the link is able to achieve 9.5Gbps with 48 byte 
MPLS packets and 10Gbps with 100 byte MPLS packets, then what is the wire 
rate?  I would say the wire rate is 10Gbps because the physical interface 
is able to forward 10Gbps.  We already have parameters for router packet 
forwarding performance - Forwarding Rate and Throughput.  I hope these 
parameters provide us sufficient coverage.

Scott P

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From: "David Newman" <[email-masked]>
Date: Mon, 22 Jan 2001 08:47:13 -0800

> I would say the wire rate is 10Gbps because the physical interface
> is able to forward 10Gbps.

No

Some physical media ALWAYS operate at X bits per second, regardless of
whether they carry packets. A measurement that says "this interface operates
at X bit/s" isn't terribly meaningful if the forwarding rate is 0 pps.

David Newman