Subject: charter goal #1a

From: Juergen Quittek <[email-masked]>
Date: Thu, 01 Feb 2001 18:45:41 +0100

Goal 1 of the suggested charter:

> Develop a standard for describing traffic flows, and for
> reporting them from a meter to a flow flow data collection
> system.  Such a standard would meet a clearly-expressed
> need for many system vendors.

For me there are two issues in here, so I start with the first
one (#1a):

> Develop a standard for describing traffic flows

  Let me give my interpretation of this phrase first:
  There are already several standards out there describing traffic
  flows. RTFM (Meter MIB) is obviously one, but there are others,
  e.g. IntServ, that include their own flow model, because they
  need one and there is no suitable standard.

  I understand this goal as an approach to a one size fits all
  traffic description. Please correct me if I'm wrong. (If I'm
  wrong, then some of the statements below are also wrong.)

- What would be the resulting benefit?
  I consider the benefit to be rather high, because, there are a lot
  incompatible flow description formats out there and for users it
  is sometimes very confusing and annoying because automatic
  translations between many of them are not possible.

- Is it or does it appear to be technically feasible?
  I doubt that it is (please object if you have a different view!).
  For some differences between existing flow description formats there
  are good reasons, e.g. because of different usage cases. Take the
  DiffServ flow model and the rtfm flow model. In DiffServ a flow can
  be described in various ways and typically with a small number of
  attributes in simple conjunctions. For rtfm, a high number of attributes
  is available and you can create complex dependencies among them.
  This would not fit DiffServ, but is quite useful for detailed traffic
  measurements.

  Maybe we can come up with a flow model fitting a restricted set of
  applications. Then we should try to identify these applications.
  
- Is "now" the right time to work on this item?
  Yes, The number of traffic flow models I see is continuously growing
  and the earlier there is a commonly usable model, the better.
  
- Can we expect sufficient support by technical,
  experts, i.e. who is willing to contribute?
  I expect this. But what I also would expect is a lot of experts
  disagreeing with the result, however it will look like, because
  they have been using different models so far and the new model
  will probably not be as well suited as their own tailored one.

- What would be the expected output documents?
  A document defining a flow model, probably based on a more basic
  information model, such as the CIM model used in the policy wg.

- What timeframe would be appropriate?
  Certainly, setting up a model could be done within some more
  than half a year. However, since this model could affect a lot
  of people I'm afraid that agreeing on a model would take very long.

- Is the IETF the right place for this item?
  Yes definitely. This is directly related to a lot of work done
  on the IP network layer.

    Juergen
-- 
Juergen Quittek     [email-masked]     Tel: +49 6221 90511-15
NEC Europe Ltd., C&C Research Laboratories   Fax: +49 6221 90511-55
Adenauerplatz 6, 69115 Heidelberg, Germany   http://www.ccrle.nec.de

---

From: Kappler Cornelia <[email-masked]>
Date: Mon, 5 Feb 2001 17:37:41 +0100

See comments inline

> -----Original Message-----
> From:	Juergen Quittek [SMTP:[email-masked]]
> Sent:	Thursday, February 01, 2001 6:46 PM
> To:	RTFM mailing list
> Subject:	charter goal #1a
> 
In fact, the goal just states a standard for describing traffic flows is to be developed. This is somewhat surprising, since, also in my view, the RTFM is just such a standard. So what was wrong with the first version? If the goal is developing a one size fits all traffic description, it should be made more clear in the charter. 

>   applications. Then we should try to identify these applications.
Or may be we just need new attributes to add to the old model. See below.
>   information model, such as the CIM model used in the policy wg.
Let me be a bit provocative here. Sorry if this was already discussed in San Diego.

Would it be a "new flow model" or just (being one-size-fits-all) the sum of all descriptions currently out there? The "new attributes" RFC already went in this direction by including IntServ and DiffServ attributes. So why not just add even more new attributes? Why a "new flow model"? What would be different? The level of abstraction?

> - What timeframe would be appropriate?> 
Cornelia

PS.: Obviously I would be willing to contribute to the work of the WG.

--------------------
Cornelia Kappler
Standards & Technology
ICM N MC ST3
Siemens AG, Siemensdamm 62, 13629 Berlin, Germany