RE: Optical Link Interface - LMP-WDM comments

[Andre Fredette <fredette@photonex.com>]

Bala,

Sorry, but I missed your attachment also.  I'll get back to you on your 
specific issues.

Andre

At 02:37 PM 7/30/2001 -0700, you wrote:
>Bala,
>
>[replying to my previous email]
>
>I just realized there was an attachment to your email.  Having gone over
>those details, I see you have given specifics to your points (1) and (4).
>Please ignore my comment for (4) - we will work on clarifications here.  I
>believe my comments on the other points, other than "What specific
>information are you talking about here?" in (1), are still valid.
>
>Thanks,
>Jonathan
>
>-----Original Message-----
>From: Jonathan Lang
>To: 'Bala Rajagopalan '; 'Andre Fredette '
>Cc: ''ccamp@ops.ietf.org' '
>Sent: 7/30/2001 1:47 PM
>Subject: RE: Optical Link Interface - LMP-WDM comments
>
>  Bala,
>   Please see inline.
>
>Thanks,
>Jonathan
>
> >-----Original Message-----
> >From: Bala Rajagopalan
> >To: Andre Fredette
> >Cc: 'ccamp@ops.ietf.org'
> >Sent: 7/30/2001 7:38 AM
> >Subject: Optical Link Interface - LMP-WDM comments
> >
> >Andre:
> >
> >I'm attaching specific comments on LMP-WDM. Top level issues are
> >as follows:
> >
> >1. Layer mix-up: In some places, the WDM system is required to
> >send information which is not native to OLS to the OXCs. In fact,
> >this is very strange, because this information must originate from
> >the OXC domain, get configured in WDM, and then go back to OXCs. This
> >is a problem with OLI definition, not LMP-WDM itself. This requires
> >some discussion and clean up.
>What specific information are you talking about here?  As you say, this
>is
>an issue with OLI definition itself and the parameters were discussed at
>quite length among both LMP-WDM authors and NTIP authors.  (I do notice
>that
>you are also listed as an OLI author...).  Certainly we can revisit
>these
>issues if they need to be addressed...
>
> >2. Rather than tailoring the procedures for the particular requirements
> >(OLI), the draft seems to be written with the goal of maximal reuse of
> >LMP. This sometimes adds to the complexity of the proposal.
>LMP-WDM was written to satisfy the OLI requirements and reuse the LMP
>protocol.  This is similar to the approach taken for GMPLS RSVP-TE and
>CR-LDP.
>
> >Specifically, LMP-WDM has many "extensions" to LMP, giving the
>impression
> >that LMP-WDM is a superset of LMP. I think there are differences in the
> >situations where LMP is applied as compared to LMP-WDM and these
>aspects
> >are not discussed sufficiently. I think a meticulous examination of the
> >OLI requirements and LMP procedures is necessary to just carve out a
>set
> >of procedures for OLI, rather than the superset approach. The maximal
> >"re-use" argument doesn't make any sense on the WDM side where there is
> >no LMP. Or, for that matter, where OXCs don't implement LMP. (This is
> >where NTIP makes a good point).
>Which LMP-WDM procedures are not required for OLI?
>
> >3. I'm afraid the current LMP link verification definition (and as a
> >corollary, LMP-WDM link verification) has only a marginal value
> >considering the investment on hardware and protocol implementation.
>This
> >is an area that requires more work.
>If you believe link verification has marginal value, you don't have to
>implement it (remember it's optional).  We have heard otherwise from
>customers.
>
> >4. Some of the procedures in the draft must be more explicitly
>described
> >rather than saying that they are same as LMP's.
>Please clarify which procedures you are referring to.
>
> >As you noted, a more careful examination of LMP itself is in order.
>This is greatly encouraged.
>
>I also think it would be useful for you to do a similar analysis of
>NTIP.
>
>Thanks,
>Jonathan
>
> >Regards,
> >
> >Bala
> >
> >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