Subject: Re: [Status] Summary of STATUS BOF and the next steps

From: [email-masked] (Noel Chiappa)
Date: Tue, 3 Sep 2013 11:35:38 -0400 (EDT)

> From: AshwoodsmithPeter <[email-masked]>

    > We are revisiting source routing with new concepts. 

The problem is that "source routing" seems, by the time you do the set-or of
all the various meanings that people apply to it, to basically mean "not
hop-by-hop routing".

The problem, therefore, with calling something "source routing" is that it's
like me calling myself "Not Peter Ashwood-Smith". The problem is that there
are a lot of people whose name is "Not Peter Ashwood-Smith", so it's really a
pretty useless name.

Similarly, saying that something is "source routing" really tells you very
little about it - except that it's not hop-by-hop. So let's find a different,
and actually meaningful, name.

	Noel

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From: Mark Townsley <[email-masked]>
Date: Tue, 3 Sep 2013 18:47:48 +0200

For those who might not be aware, the homenet WG has been actively working on "source and destination routing" (SADR) techniques to solve the routing problem facing a multi-router, multi-homed, multi-prefix, IPv6 home network:

A few refs:

draft-troan-homenet-sadr
draft-baker-ipv6-ospf-dst-src-routing
draft-baker-ipv6-isis-dst-src-routing
draft-boutier-homenet-source-specific-routing
draft-baker-rtgwg-src-dst-routing-use-cases

We're working with the ADs on where to advance this, including the possibility of the rtgwg (hence baker's rtgwg document listed above). Whatever ends up coming out of homenet, rtgwg, and the WG that is forming here, we should aim to be very clear what is what. 

- Mark

P.S. Another ref, just for kicks: http://www.youtube.com/watch?v=3Omg1lJ6EQI

On Sep 3, 2013, at 5:35 PM, Noel Chiappa wrote:

> _______________________________________________
> status mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/status

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From: "Carlos Pignataro (cpignata)" <[email-masked]>
Date: Tue, 3 Sep 2013 17:18:00 +0000

This is another datapoint against using "source routing" -- the term is overloaded with multiple meanings and history including "providing routing information at the source", use of SRR options, and "making a routing decision based on a source address".

"Segment Routing" is simple and captures the essence of the work (including non explicit -- meaning IGP selected -- paths).

Thanks,

-- Carlos.

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From: "Adrian Farrel" <[email-masked]>
Date: Tue, 3 Sep 2013 22:13:36 +0100

Hi Mark,

The term "source routing" in the homenet context appears to apply to the concept
of considering the source address at the time of making a routing decision,
rather than the imposition of a route by the source node. Thus, what homenet is
doing is a form of policy-based routing (where the policy applies to the source
address).

It may be the case that the homenet problem space overlaps somewhat with the
STATUS work, but it looks like STATUS is considering a wider set of problems and
networks with larger diameters.

[snip]

> We're working with the ADs on where to advance this, including the possibility
of
> the rtgwg (hence baker's rtgwg document listed above). Whatever ends up
> coming out of homenet, rtgwg, and the WG that is forming here, we should aim
> to be very clear what is what.

I haven't been involved in that discussion (yet), but I note that the homenet
charter says...

 If it turns out that additional 
 options are needed for a routing protocol, they will be developed in 
 the appropriate Routing Area working group, with the HOMENET working 
 group providing the architecture and requirements for such 
 enhancements.

But you're right. We need to be clear on terminology and division of labor.

Thanks for raising this.

Adrian