Subject: [manet] R2RI Framework and Requirements

From: "Cheng, Bow-Nan - 0665 - MITLL" <[email-masked]>
Date: Fri, 10 Feb 2012 13:19:49 -0500

Hi all,

Back in Sept and November 2011, there was some discussion on the list of potentially authoring some framework to help discuss and evaluate radio-to-router interface (R2RI) protocol technology (such as DLEP).

We've put together a start on that framework for consideration for adoption by the MANET WG and would love your feedback.

A new version of I-D, draft-bcheng-r2ri-framework-00.txt has been successfully submitted by Bow-Nan Cheng and posted to the IETF repository.

Filename:  draft-bcheng-r2ri-framework
Revision:  00
Title:  Radio to Router Interface Framework and Requirements
Creation date:  2012-02-13
WG ID:  Individual Submission
Number of pages: 14

Abstract:
   In highly dynamic, heterogeneous radio MANET environments where links
   are constantly changing, standardizing information exchange between
   the radio and router such that routers can make informed  routing
   decision based on link layer information over heterogeneous link
   types becomes a key area to address. This document defines the basic
   framework for radio-to-router interface communications as well as
   requirements and considerations for evaluating radio-to-router
   interface technologies for use in MANETs.

https://datatracker.ietf.org/doc/draft-bcheng-r2ri-framework/?include_text=1

-Bow-Nan

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From: <[email-masked]>
Date: Fri, 10 Feb 2012 22:43:54 +0000

Router-smart-modem interface technology isn't only applicable to MANETs - consider DVB-S2 ACM/VCM deployed on satellite links, or how varying ADSL can support the networks behind it as rate change and QoS get reconfigured.

Some more general thoughts on this are in the documents at:
http://personal.ee.surrey.ac.uk/Personal/L.Wood/router-modem-integration/

Lloyd Wood
http://sat-net.com/L.Wood/

________________________________________
From: [email-masked] [[email-masked]] On Behalf Of Cheng, Bow-Nan - 0665 - MITLL [[email-masked]]
Sent: 10 February 2012 18:19
To: [email-masked]
Subject: [manet] R2RI Framework and Requirements

Hi all,

Abstract:

-Bow-Nan

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From: Juliusz Chroboczek <[email-masked]>
Date: Mon, 13 Feb 2012 20:08:37 +0100

Hi,

Interesting model.  A few quick comments after a first reading.

The draft speaks of "link metrics" which it doesn't define.  Are these
physical layer data or the metrics used by the routing protocol?  In
other words, who is in charge of munging the physical layer information
in order to compute the layer 3 metric -- the router or the radio?

My reading is that you mean the former (the radio provides raw lower
layer data which the router uses to compute a routing protocol metric),
in which case I suggest that this should be made explicit.  It should
also be made explicit whether the other model (in which the radio cooks
a single value which the router copies as-is into its RIB) is or isn't
out of scope for R2RI (I think that Section 4.10 implies that it's out
of scope).

On a different note, it would be helpful if the draft provided
a representative list of physical layers that are to be supported (it
mentions unspecified "TDMA schemes" in Section 4.9 and 802.11 ad-hoc in
Section 5.7, but it would be nice to have a more representative list
were provided).

Minor nits:

In Section 4.7, "affect" instead of "effect".

In Section 4.12, extraneous comma before "offer unique challenges".

In Section 5.5, "affect" instead of "effect" (twice).

In Section 6, "This document does not address security considerations."
Yes it does, in Section 4.15.

Regards,

-- Juliusz Chroboczek

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From: "Cheng, Bow-Nan - 0665 - MITLL" <[email-masked]>
Date: Tue, 14 Feb 2012 10:46:49 -0500

Hi Juliusz,

Thanks for your helpful comments. I will define link metrics in the next
draft, but you are correct in that these are radio-specific metrics (link
layer) that are sent to the router. The way its currently done in practice
is that the metrics are provided in raw format, and the routing protocol
dynamically calculates a cost based on the link metrics:

See an example here:
http://www.cisco.com/en/US/docs/ios/12_4t/ip_mobility/configuration/guide/i
p_manet.html

I think there's a lot of potential for doing routing w/ link metrics
better than coming up with 1 cost.. But it is beyond the scope of the
document. 

I will incorporate the other suggestions. Thanks!

-Bow-Nan

--
Bow-Nan Cheng, Ph.D.
MIT Lincoln Laboratory
Airborne Networks Group
244 Wood St Lexington MA 02420
781-981-4997