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Minutes of the Benchmarking Methodology Workgroup 

Report by Kevin Dubray

Approximately 45 people attended this meeting. 

1. Agenda.

The proposed agenda for this BMWG was accepted as follows: 

- Administration
- Discussion of Proposed Cell/Call benchmarking - Discussion of LAN 
Switch Draft

2. Administration.

Kevin Dubray introduced himself as co-chair of the BMWG, replacing 
Jim McQuaid. Jim was thanked for his service. Dubray also reminded 
attendees of the meeting time and place of the IP Provider Metrics 
(IPPM) half of the BMWG.

It was announced that the "Benchmarking Methodology for Network 
Interconnect Devices" draft was approved as an informational RFC 
1944. 

It was reported that a discrepancy had already been found in RFC 1944 
with regards to a range of addresses. Scott Bradner informed the group 
that the error was reported to the RFC Editor. As of the meeting, Scott 
had not heard back.

A question was raised on what to do in the interim with anomalies 
found in BMWG documents. It was offered that a list of "Outstanding 
Issues" would be offered periodically through the BMWG mailing list 
and stored via the archive. Dubray volunteered to manage this. 

Dubray mentioned that the BMWG charter and goals were updated to 
better reflect the other BMWG effort, IPPM, chaired by Guy Almes. 
The charter can be accessed via the URL:

http://www.ietf.cnri.reston.va.us/html.charters/bmwg-charter.html 


3. Workplan - Proposed Cell/Call Benchmarking. 

An assignment from the last BMWG meeting, Dubray presented his 
action item for a proposed Cell/Call Benchmarking workplan that was 
previously distributed on the mailing list. Given the cell focused 
benchmarking activities of other organizations (ATM Forum, ITU-T, 
etc.), the scope of the proposed workplan focused on the definition of 
the terminology and methodology of benchmarking cell-
forwarding/connection-oriented devices in PACKET-BASED 
internetworks.

A vote was made on whether to proceed with the workplan. There was 
consensus that the group move forward with this effort. 

The workplan suggested that the effort be split into two distinct parts: 

1. Draft a document identifying or defining the relevant terminology 
and metrics in characterizing the performance of these devices. 

2. Draft a document defining the methodology of collecting the metrics 
produced in the Terminology document. 

Item 2 would only occur after consensus was reach on Item 1. 

A volunteer was solicited to head the Metric and Terminology effort. 
Robert Craig gratiously volunteered. Robert is to make an initial draft 
available on the mailing list.


4. LAN Switch Benchmarking Draft.

Bob Mandeville was on hand to discuss the latest revision of the LAN 
Switch Benchmarking Draft. This draft has evolved significantly since 
its last version. In the latest version, Bob modified the draft to: 

- Focus on the identification of related metrics and terminology, much 
like RFC 1242.

- Expand the draft's scope beyond Ethernet switches. 

There was a discussion on how various media will be supported, given 
the inherent differences between, for instance, deterministic media and 
contention-based media. Bob's response was to have a master document 
that would attempt to address issues in a most generic fashion. When 
specific topics warranted a more focused discussion, separate memos 
addressing these issues could be issued.

An issue was brought up that most of the suggested metrics' stimuli were 
monolithic in style; further, the stimuli were offered outside the 
context of any application. It was cited that application-specific tests 
introduced many variables that made characterization difficult (e.g. 
How does running a file transfer on a 8086 PC vs Pentium-based PC using 
different protocol stacks, affect a switch's benchmark?) Another 
example, however, was offered citing the need to distinguish how a 
switch handles that file transfer in light of, say, video traffic. It was 
agreed that reliance on one specific application or another wasn't 
necessarily desirable. However, that is not to say that the use of 
generalized, application-like stimuli (e.g., the bursty nature of data 
transfers vs. more "constant" bit rate of video) isn't undesirable. 
Further, it may be desirable to see how the application of one stimulli 
impacts the other across the tested system.

On the draft's discussion of bursts, Bob was cautioned that it was one 
thing to say, "Traffic is bursty,"; characterizing traffic as a "burst of 
one," is saying something else.

The multidimensional traffic item was brought up. Several examples 
were offered (e.g., broadcast, multicast, Full Duplex Ethernet) on why 
it was difficult to characterize the behavior of a system with the use of 
multidimensional traffic. The consensus appeared to be that this is a 
useful concept if and only if the impact of the stimuli on the tested 
system could clearly be ascertained and communicated. 

Bob asked whether jitter should be a addressed in the document. A 
comment was made to the effect that if you consider jitter, you should 
consider both the VBR and CBR cases, but only if you can clearly 
describe the observed behavior.

Bob queried the group as to whether the document should attempt to 
define a switch. The group generally agreed that there was more 
marketecture than technology these days in the taxonomy of a switch. 
Further, if there was enough distinct qualities between a generic 
switch, a Layer 2 switch or a Layer 3 frame/packet switch, subsequent 
work could address those features specifically. It was offered that 
regardless of the "type" of LAN switch, most of the concepts offered in 
the current draft could be applied. 

In general, there was a positive air regarding the draft. Bob was going 
to put the latest draft on the mailing list for further discussion. The 
draft should be discussed enough on the mailing list so that by the next 
meeting, the draft can be forwarded for consideration as a RFC.


5. Assignments & Goals:

The next round of goals slated for the BMWG by the next meeting are: 

1. Present for discussion a preliminary draft on the Benchmarking 
Terminology for Cell Forwarding/Connection-Oriented Internetworking 
Devices. (Robert Craig)

2. Prepare the LAN Switch Benchmarking Terminology Draft to the 
point where its ready to forward for consideration as a RFC by next 
meeting. (Bob Mandeville)


The meeting concluded with Dubray requesting that people monitor and 
participate in the discussions on the BMWG mailing list so that 
expeditious progress can be made in the above areas.