The MPLS WG Archive

[Alex Zinin <azinin@cisco.com>]

Bala,

In addition to what Yakov said, I wanted to emphasize that
draft-kompella-mpls-unnum introduces a generic mechanism
(not specific to link bundles) to perform announcement of
and LSP signaling across unnumbered links, which is
necessary regardless of whether you bundle or not.

-- 
Alex Zinin


Monday, October 16, 2000, 12:58 PM, Bala Rajagopalan <braja@tellium.com> wrote:

> Hello,

> I agree that bundling and flooding optimization are separate
> mechanisms. But if a particular bundling scheme necessarily results in multiple
> adjacencies, then flooding optimization would be adviced. Of course,
> a claim can always be made that flooding opt. is optional and
> orthogonal, but if it is not used in this case, I don't see its utility.
> Thus, IMO, draft-kompella-mpls-bundle... creates a neccesity
> for flooding opt.Furthermore, this bundling approach
> requires the support for multiple unnumbered links (bundles),
> (i.e., draft-kompella-mpls-unnumbered-xx.txt.)

> Now, the bundling scheme proposed in our draft addresses
> SRLG-based bundling, and it results in a single adjacency.
> For optical network applications, this obviates a need for
> any type of flooding optimization. And, there is no need to
> support extensions for multiple unnumbered links. In esssence,
> the simple device of link groups eliminates the need for two
> other extensions, one in routing, another in signaling.

> Other than this, the parameter descriptions in our draft are
> pretty straightforward, link type descriptions that suit SONET
> link types.

> Our bundling proposal doesn't preclude the use of separate
> bundle for each link group (along with support for
> flooding opt., and multiple unnumbered bundles). In this sense, our
> proposal is more flexible. I really don't
> see why there should be an objection to it.


> Regards,

> Bala

> Alex Zinin wrote:

>> Agree 100%.
>>
>> We have 3 techniques that are somewhat related, but yet orthogonal:
>>
>> 1. Link bundling
>> 2. Control channel[s] for link bundles (LMP)
>> 3. IGP flooding optimizations
>>
>> Link bundling allows to summarize the TE information.
>> LMP allows to minimize the number of adjacencies per bundle
>> (note that LMP will not have to be implemented on each type
>> of links), and flooding optimizations minimize overhead traffic
>> over parallel adjacencies.
>>
>> Alex.
>>
>> Monday, October 16, 2000, 9:05 AM, Curtis Villamizar <curtis@workhorse.fictitious.org> wrote:
>>
>> > Bala,
>>
>> > I remember there being consensus at Pittsburgh on making the Kompella
>> > bundles draft a WG item.
>>
>> > Use of the flooding optitimization is one means of improving the
>> > efficiency of the IGP and is a separate issue.
>>
>> > Both the bundles and the flooding optitimization can stand alone.
>> > Neither one depends on the other.  If used together they may
>> > complement each other but use of either one separately is possible and
>> > useful.
>>
>> > I don't see that any changes are required to the bundles draft to
>> > accommodate the flooding optitimization.  If changes are required,
>> > please point them out.
>>
>> > Curtis

> --

> Bala Rajagopalan
> Tellium, Inc.
> 2 Crescent Place
> P.O. Box 901
> Oceanport, NJ 07757-0901
> Tel: (732) 923-4237
> Fax: (732) 923-9804
> Email: braja@tellium.com