Subject: Questions regarding the new TBRPF-draft

From: [email-masked]
Date: Tue, 30 Oct 2001 14:04:16 +0100 (CET)

Hello all,

Returning from vacation, I find a new version of the tbrpf-draft
draft-ietf-manet-tbrpf-02.txt) available.

It seems to me that the new draft does not contain any of the material
presented by the authors at the meeting in London (periodic updates,
multipoint relays and focus on partial topology diffusion etc.).

If I am right, then I am curious to know what facts have supported the
decission to discard those proposed "new" things - in particulary
considering the enthusiasm with which they were presented at the meeting.

I am also surprised that two non interoperable versions of tbrpf (ft and
pt - they are non-interoperable, right?) remain in the same draft.

-- 

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  Thomas Heide Clausen
  Civilingeniør i Datateknik (cand.polyt)
  M.Sc in Computer Engineering

  E-Mail: [email-masked]
  WWW:    http://www.cs.auc.dk/~voop
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From: [email-masked]
Date: Wed, 31 Oct 2001 11:23:21 -0800

> pt - they are non-interoperable, right?) remain in the same draft.

Thomas,

I am glad you asked these questions, since these are things I would
like to clarify. The main change we made to the TBRPF draft was the 
neighbor discovery protocol, which was an important change that I 
presented in London.  (Therefore, your statement that the current 
draft does not contain any of the material presented in London is not 
quite accurate.)  Since the new neighbor discovery protocol had already 
been implemented and tested, it was ready to be included in the draft; 
but we wanted to implement and test the other new features (including 
a combination of differential and periodic updates) before including 
them in the draft. The new version of TBRPF (which includes the new 
features) has now been implemented in Linux and ns-2, and we plan to 
release the source code and updated draft within the next few weeks.  
Can we also obtain your ns-2 code for OLSR?

As for using MPRs, as I explained in my post to manet dated 8/21
and in my response to Philippe on 8/22, the new version of TBRPF 
does not use MPRs (as defined in OLSR). I don't want to repeat what 
was said in those messages; but in summary, there is a similarity 
between parents and MPRs, the main difference being that parents are 
selected by the children (which are upstream on the data path) while 
MPRs are selected by the MPR source (called the "MPR selector" in OLSR,
which is downstream on the data path). I did present an *option* for TBRPF 
to use source-selected MPRs (as an attempt to merge TBRPF with OLSR),
but we have decided not to include this option in the next draft.

You are correct that the FT and PT versions of TBRPF as described in
versions 01 and 02 of the draft were actually two different protocols 
(although both use the same neighbor discovery protocol), which I stated 
during my presentation in London.  However, we have now merged them into 
one protocol, which will be described in the next version of the draft.
Each node will be required to report the minimum topology information, 
and has the option of reporting additional topology information (e.g.,
to increase robustness).

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Richard Ogier
Sr. Research Engineer
SRI International
[email-masked]
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