Subject: Re: Reviewing batman-adv for net/

From: Henning Rogge <hrogge-gM/[email-masked]>
Date: Mon, 28 Jun 2010 07:32:12 +0200

Am Montag 28 Juni 2010, 01:15:23 schrieb Marek Lindner:
> the OLSR as standardized by the IETF is known to be flawed when used
> outside of a simulator (even the IETF Manet people know this - I spoke
> with one of them). We have assembled a few documents explaining some of
> its weaknesses on our website (www.open-mesh.org) but I suggest you get in
> touch with the folks of www.olsr.org. They can go into the details of why
> they don't follow the RFC.
OLSRv1 lacks the support for routing metrics in the IETF RFC document. Most of 
the research groups began integrating routing metrics later, and OLSRv2 (which 
is worked on at the moment, 2 RFC's done, 1 at IESG, 1 as a draft) will 
contain specified ways to include a routing metric on a link and how to use 
it. We were talking about the generic metric encoding some weeks ago on the 
MANET WG list.

Using hopcount metric (as described in the RFC 3626) will result in a "worst 
link first" strategy in wireless networks, because you always optimize for 
long links which will break often.

It's not difficult to integrate a routing metric into OLSRv1, but in the old 
OLSRv1 RFC (2003) there it's not specified. We (the olsr.org team) use a 
custom message format to add metric information to our hello/tc messages, the 
NRL use a different one for their own metric aware OLSR.

Henning Rogge (olsr.org team)

-- 
1) You can't win.
2) You can't break even.
3) You can't leave the game.
— The Laws of Thermodynamics, summarized