EditorŐs note:  These minutes have not been edited.


Minutes of the Realtime Traffic Flow Measurement Working Group 
(RTFM) 

35th IETF, Los Angeles, Wed 6 Mar 96

Chairs: Nevil Brownlee, Sig Handelman

Minutes by: Cyndi Mills & Nevil Brownlee 

The group's charter and milestones were reviewed and confirmed. 
Nevil Brownlee gave a brief overview of the Traffic Flow Measurement 
model, and of NeTraMet (his public-domain implementation). Sig 
Handelman gave a status report of the IBM implementation. 

Existing work on traffic flow measurement was discussed, particularly 

- The work of the NLANR group at the San Diego Supercomputer 
Centre 
(see http://www.nlanr.net/NA for a good introduction). - A journal 
article on "Measurement, Modelling and Emulation of Internet 
Round Trip Delays" was discussed. The reference has been posted to the 
mailing list.
- The Flow Statistics provided by Cisco's Flow switching option for 
their high-end routers.
- The work of other IETF Working Groups such as BMWG/IPPM, RMON 
and RSVP. 

The distinction between this group and IPPM was discussed. IPPM is 
concerned with measurements which a user may use EXTERNALLY to 
measure an ISP's performance, while RTFM provides instrumentation 
which may be used INTERNALLY in an ISP's network to measure flows 
and performance. Steve Corbato gave a short presentation of his recent 
work on high-speed polling of router variables.

We will publish a detailed list of references to these on the RTFM Web 
page (http://www.auckland.ac.nz/net/Internet/rtfm/TOP.html). 

The 'Flow Measurement: Architecture' Draft was reviewed. Many 
people asked interesting questions, but only editorial changes were 
requested. We will run a two-week call on this draft, make these 
changes so as to produce a new Draft early in March. After a two-week 
last call we will submit this Draft to IESG for publication as an 
experimental RFC. 

The 'Flow Measurement: Meter MIB' document was reviewed. A number 
of significant changes to this have been suggested since it was 
published in mid-February. These will be made, and a new draft 
published. If - after a two-week last call - there are no requests for 
further changes, we will submit this Draft to IESG for publication as an 
experimental RFC. 

Two further new Drafts, 'Flow Measurement: Background' and 'Flow 
Measurement: Experience' will be prepared before the Montreal IETF 
meeting. These are intended for publication as information RFCs. 

The group's next work item, a revised version of the traffic flow model, 
was considered. Two topics of interest were raised: 

- How well does the meter cope with running out of resources? 
Switching to a standby rule set so as to reduce the rate new flow records 
are created has worked well in practice, but we should consider sending 
an alarm request to the manager. 

- Would it be sensible to have a hard disk in the meter? 
This would make the meter less simple than it is now, but it would let 
the meter save its configuration data such a rule sets so that it could 
restart after a power outage without needing a download from the 
manager. It would also allow the meter to write its flow table to disk 
when a manager commanded it to do so. 

We will collect further ideas on the mailing list for discussion in 
Montreal.

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