Subject: RE: Comments on Multicast Methodology Draft

From: Kevin Dubray <[email-masked]>
Date: Fri, 07 Jul 2000 17:57:53 -0400

Forwarded for Debby Stopp.

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Replies to Jerry's comments:

1 - Changed all references to "receiving ports" to "destination ports" for
consistancy.
2 - Modified reference to "non-homogenous network environment" to
"simulating a non-homogenous IP payload environment"; to clarify, we are not
talking about the underlying topologies, we are referring to the IP traffic
modeling content.
3 - Changed terminology reference to "bandwidth" to "total traffic flow" &
"forwarding rates" where appropriate.
4 - Changed terminology reference to "line rate" to "maximum offered load"
5 - Modified the appendix so that it functions merely as an explaination -
an equation really doesn't apply in this case; the main purpose for this
appendix was just to defined the difference between homogenous vs.
non-homogenous packet distribution.

Modified version to follow w/in the next day or so.

Debby Stopp
Principal Software Engineer
(818) 444-2365

Ixia
26601 W. Agoura Rd.
Calabasas
CA 91302
Tel: 818 871 1800 (US) +1 818 871 1800 (international)
http://www.ixiacom.com

Ixia...
      When the test really counts.

-----Original Message-----
From: [email-masked]
[mailto:[email-masked]]On Behalf Of Perser, Jerry
Sent: Thursday, June 22, 2000 8:52 AM
To: BMWG (E-mail)
Subject: Comments on Multicast Methodology Draft

I have a few comments on the draft:
Every test starts with a definition, but no objectives.  I am not sure why
restating RFC 2432 is so important.  In the introduction you tell the reader
to read RFC 2432.  What would be very helpful is an objective (see RFC 2544)
to each of the tests.
Some of the terminology used is confusing:
1. "Destination ports" versus "receiving ports".  Section 3 uses both terms.
At first I though these were the same thing.  At second glance, maybe they
are two different things.  Can you clarity what a "receiving port" is and
what a "destination port" is?  How are the related?
2. "Non-homogenous network environment".  This infers something is
dissimilar in the network, but does not state if it is layer 1, layer 2,
layer 3.  The first time I read this I though Ethernet versus ATM.  Is the
term mixed-class more appropriate?
3. "Bandwidth".  This term has not been defined by the IETF.  I have seen it
used in two in different definitions.  The current definition is to add the
offered load to the forwarding rate to find the bandwidth of a switching
device.  I don't know who's marketing department started this (I have heard
two different stories) and I don't agree with it.  We SHOULD avoid this term
until it is clearly defined in an RFC like throughput, or Maximum Offered
Load.
4. "line rate".  RFC 2285 defined a term Maximum Offered Load.  Can we use
this term instead of a non-IETF term?
Where are Appendix A equations? Appendix A has a discussion and an example
of a method for distribution.  But there are no equations, formulas or
pseudo code.  I have asked for this two times already.  Are the equations
proprietary?
___________________________________________________________
Jerry Perser               Phone: 818.676.2320
SmartLab Manager           Lab:   818.676.2337
Netcom Systems Inc.        Fax:   818.880.9165
26750 Agoura Road          Corp:  818.676.2300
Calabasas, CA, 91302       Pager: [email-masked]