Subject: partially meshed

From: "Debby Stopp" <[email-masked]>
Date: Wed, 17 Nov 1999 14:11:35 -0600

One of the comments at the meeting that I did not get the opportunity to
make was that I noticed a test name "Partially Meshed Overloading" in the
mswitch document.  I'm confused by this test/test name; while the name of
the test led me to believe it is a congestion-oriented test, the description
of the test does not.

My understanding of the partially meshed is that all transmitting ports
transmit only, all recieve ports recieve only.  There are several traffic
patterns that accomplish this task:

- one TX port transmitting to many recieve ports;
- many TX ports transmitting to one receive port; and
- many TX ports transmitting to many recieve ports, more or less half of the
fully meshed test scenario.

I did found in the document two other test descriptions, the "partially
meshed multiple devices" & "multiple streams of unidirectional traffic".
These tests appear to more or less encompass the above traffic patterns;
however from the names of these tests & their objectives, it is not clear to
what extent each test differs from each other.

As these 3 tests appear to be just a variation of the partially meshed
terminology/definition, I would find it very helpful if they were moved into
their own section w/3 parts each describing the difference & renamed
appropriately.  The section would then only require one overall paragraph
describing  the setup parameters & the differences would be more apparent.

Debby Stopp
Sr. Software Engineer
Ixia Communications
4505 Las Virgenes Road, Suite 209
Calabasas, CA 91302
Tel: 818 871 1800 x107
Fax: 818 871 1805
[email-masked]
http://www.ixia.com/

Suddenly.....

    Performance Testing That Is Anything But Standard.

---

From: Jerry Perser <[email-masked]>
Date: Thu, 18 Nov 1999 11:10:53 -0800

First, there is not a one-to-one relationship between the terminology and
the methodology.  It will take several terms to construct one methodology,
and several methodologies will use the same term.  For example the
congestion control test (previously HOLB) uses the terms Frame Size,
Interframe Gap, maximum offered load,  Frame Loss Rate, offered load,
Forwarding rate, Head of Line Blocking, and backpressure.  These terms were
defined in RFC 1242 and RFC 2285, but combined for one test methodology.

> the test led me to believe it is a congestion-oriented test, 

The name came from the fact that a many-to-one test can overload the
DUT/SUT.  Congestion can occur during testing.  By reading the objectives,
do you have a better term to describe the test?
 
> transmit only, all recieve ports recieve only.  There are
                        ^
                        I before E except after C 
> several traffic

RFC 2285 did not address partially meshed bi-directional traffic.  This
draft does.  RFC 2285 does not address non-meshed bi-directional traffic,
this is covered in RFC 2544 section 14.

> what extent each test differs from each other.

Read the first paragraph above.  Which ONE of the test's objectives is not
clear?
 
> describing  the setup parameters & the differences would be 

If you read RFC 2285, section 3.3.2, last paragraph in the discussion, you
will see that a partially meshed is just a variation of fully meshed.  The
objectives for each of the 3 partially meshed tests and the fully meshed are
different, therefore different sections. 
 
>     Performance Testing That Is Anything But Standard.
 
I still don't understand this statement.  If a standard test is defined in
an RFC, you will do testing that is anything but what is defined in the RFC?
This implies non-standard testing.