The MPLS WG Archive

[Bora Akyol <akyol@pluris.com>]

Eric

As I mentioned in my previous email, I would be happy to write an ID that
describes our approach and work with the community to make it an open
standard.

I believe that the bonding of L1 links into one bonded (bundled) L2 link is
something that should be protocol-neutral and should work with all L3
protocols. I believe that such an abstraction is possible and is actually
fairly straightforward to implement and provides a coherent framework that
one can use to ask questions like if protocol X were to run over a bonded
link, how would it run; and then actually answer it in an easy manner.

Thanks for the comments,

Bora


Eric Gray wrote:

> Bora,
>
>         I essentially agree with the observation that
> link bundling is not inherently an MPLS issue and I
> also feel that this draft - at least as is - should
> not be adopted by the MPLS working group.  However,
> my reasoning is slightly different than yours.
>
>         While the draft does include a lot of stuff
> that is specific to MPLS, it also includes a ton of
> IS-IS and OSPF specific stuff as well.  My sense is
> that it actually has significantly more non-MPLS
> related stuff in it than MPLS related stuff.  Other
> people may disagree but, at the very least, this
> work should be done in a forum that is less focused
> on label switching and more focused on routing.
>
>         I do not think it is very useful to provide
> examples of proprietary approaches to solving the
> problem.  It takes two to bundle links.  But, if
> your point is that it may be a good idea to back
> away from a link-bundling scheme that is particular
> to MPLS LSP based links, I think it is a good point.
>
> --
> Eric Gray
>
> > -----Original Message-----
> > From: Bora Akyol [mailto:akyol@pluris.com]
> > Sent: Friday, July 07, 2000 11:39 AM
> > To: George Swallow; mpls@UU.NET
> > Subject: Re: Link Bundling
> >
> >
> > George, Yakov, et al.,
> >
> > I do not think that this internet draft should be adopted as an MPLS
> > working group document. My primary objection to this document
> > is the fact
> > that bundling of L1/L2 interfaces has nothing specific to do
> > with MPLS.
> > In fact, this is an L2 abstraction that should be completely
> > transparent
> > to MPLS, IP or ISIS. I feel that this particular draft is
> > very focused on
> > MPLS-specific concerns and does not provide a good
> > abstraction of the L2
> > bundling aspects and also places significant restrictions on
> > what can be
> > done with a bundled link and what kind of members it can have.
> >
> > I personally know of at least one implementation (ours) of
> > bundled links
> > that forms such an abstraction to all upper layer protocols. In this
> > implementation, a heterogeneous group of L1/L2 interfaces are bonded
> > together at L2 NCP layer such that IP NCP, MPLS NCP, ISIS NCP
> > treats the
> > bundled (bonded) interface as just another type of interface.
> > When MPLS
> > RSVP messages are passed over the bundled interface, the
> > labels that are
> > assigned are programmed into all members of the bundled links
> > even though
> > in reality a hash is used so that only one of the members are used (to
> > prevent reordering). Bandwidth management is handled by means of the
> > apriori knowledge of the hash. Also note that this particular
> > implementation is not MLPPP since no additional headers are
> > added to the
> > packets.
> > For MPLS specific concerns, the methods that are used in this approach
> > can be expanded. For IP, this particular approach works very well.
> >
> > If there is interest from the MPLS WG, we (myself and another
> > colleague)
> > would be perfectly willing to author an Internet Draft on
> > this particular
> > bond implementation. The question that I have is what is the
> > proper forum
> > to submit a generalized layer 2 bundling draft in the IETF. It is
> > certainly relevant to MPLS, but it is just as relevant to IP,
> > ISIS, etc.
> >
> > Regards
> >
> > Bora Akyol
> >
> >
> > George Swallow wrote:
> >
> > > > Folks,
> > > >
> > > > Kireeti and myself would like to ask the MPLS WG to
> > > > accept draft-kompella-mpls-bundle-01.txt as an
> > > > MPLS WG document.
> > > >
> > > > Yakov.
> > >
> > > Consensus on this will be assessed on 7/12.  Opinions
> > should be aired
> > > by then.
> > >
> > > ...George
> > >
> > > ==================================================================
> > > George Swallow       Cisco Systems                   (978) 244-8143
> > >                      250 Apollo Drive
> > >                      Chelmsford, Ma 01824
> >
> >
> >