Subject: ifSpeed and a few questions

From: Michael Welzl <[email-masked]>
Date: Mon, 22 Nov 1999 16:17:43 +0100

Hi,

I can't see why this part of the ifSpeed definition ...

"An estimate of the interface's current bandwidth in bits
per second.  For interfaces which do not vary in bandwidth
or for those where no accurate estimation can be made, this
object should contain the nominal bandwidth."

... has not changed yet; it's still the same in
draft-ietf-ifmib-ifmib2-01.txt

I believe that ALL interface running IP vary in bandwidth, so
ifSpeed will ALWAYS contain the nominal bandwidth.

I wrote "The Performance Transparency Protocol (PTP)"
( draft-welzl-ptp-01.txt ). In this draft, I make use of the
nominal bandwidth as well as the "ifMTU", "ifInOctets" and
"ifOutOctets" objects. Is it appropriate to use ifSpeed for
the nominal bandwidth?

I invite you to take a look at the draft and let me know if the
MIB references are okay - I don't think it makes much sense to
redefine everything from scratch.
How do I refer to if-objects from MIB-II in the most flexible
way? If an object is changed, I would like implementors to use the
most recent definition, but only if it's backwards compatible.

Regards,
Michael Welzl

---

From: Ted Brunner <[email-masked]>
Date: Mon, 22 Nov 1999 10:26:47 -0800

> ifSpeed will ALWAYS contain the nominal bandwidth.

Hmm.  Some interfaces have a fixed bandwidth (eg. 10M Ethernet)
others have a varying amount (eg. some tunnel) for which there is
no nominal rate, and estimation is the only option.
Since an interface, in the sense of IF-MIB, may be either a physical 
interface or a virtual/higher-layer thing, the objects must have 
some kind of duality in their definitions.

-- 

Ted Brunner		VideoTele.com
			Tektronix
			MS 50-475
[email-masked]	14150 SW Karl Braun
503.627.1317		Beaverton OR 97005