RE: Optical Link Interface

["Osama Aboul-Magd" <[e-mail]>]

Andre,

Obviously I disagree with you in your conclusion. There are number of
factors that should be considered:

- While LMP has been in STANDARD process for some time, there hasn't been
much deployment, if any, of it. Furthermore the reality of optical networks
today is that same vendor equipment is deployed in a single span.
Implementation of LMP in this case is at best optional. One may choose not
to implement LMP at all. IMHO tying this important interface to the fate of
LMP is not the way to proceed. How long LMP been at the IETF is irrelevant.

- NTIP is a new TCP application in the same way as LMP-WDM is a NEW
application for LMP. 

- The issue is not really LMP vs TCP. NTIP and LMP-WDM differ in the model
itself. Your choice to use LMP to run LMP-WDM on top of it forced you to
treat the PXC and LS as peers. NTIP treats PXC-LS relationship as
master-slave. Non peer relationship suits this interface better.

- To link with other standards bodies, as far as I know T1X1, where the
optical knowledge exists, is yet to arrive to a definition of this
interface. More contributions are solicited to better understand its need
and applications. Given that, I'd like to understand the rationale for the
"rough consensus" reached at CCAMP mailing list. Only 4-5 messages were
posted to the mailing list and mostly from authors of the OLI requirements
draft.

- I don't see harm in having two protocols. The market made its decisions on
the examples you mentioned, and I am sure it will happen again in this case.

Regards;

Osama Aboul-Magd
Nortel Networks
P.O. Box 3511, Station "C"
Ottawa, ON, Canada
K1Y - 4H7
Tel: [phone]
e.mail: [e-mail]

 -----Original Message-----
From: 	Andre Fredette [mailto:[e-mail]] 
Sent:	Monday, July 23, 2001 10:01 PM
To:	[e-mail]
Subject:	Optical Link Interface

Last month, the "Optical Link Interface (OLI) Requirements" document
http://search.ietf.org/internet-drafts/draft-many-oli-reqts-00.txt
was discussed on the ccamp mailing list and achieved "rough consensus"
according to our working group co-chairs.  Given this, we'd like to make
some progress on the protocol specification.  I'd like to generate some
discussion on this mailing list before the IETF meeting in London because
meaningful technical discussion cannot occur in the time allocated during
the meeting.

There have been two proposals in the IETF to satisfy the OLI requirements:

1. [LMP-WDM]:
"Link Management Protocol (LMP) for DWDM Optical Line Systems"
http://www.photonex.com/other/draft-fredette-lmp-wdm-02.txt
(note, this updated document was submitted Friday, so it should show up
on the official website soon).

and

2. [NTIP]:
"Network Transport Interface Protocol (NTIP) for Photonic Cross Connects"
(PXC) http://search.ietf.org/internet-drafts/draft-sahay-ccamp-ntip-00.txt

LMP-WDM proposes extensions to LMP to satisfy the OLI requirements, while
NTIP proposes a new protocol.  We believe that the LMP approach is best
because:

1. [LMP-WDM] satisfies the OLI Requirements.

2. The extensions to LMP are quite natural and fit within the spirit of the
LMP protocol.

3. LMP is a reasonably mature IETF protocol specification:
     - It has been in the works for well over a year.
     - It is an official working group document.

4. It is better to have one protocol, than two for a given function
(remember CR-LDP vs. RSVP-TE, and OSPF vs. IS-IS)

5. Using the same protocol simplifies both implementation and management on
devices, such as optical cross-connects and routers, that may need to use
both simultaneously.

While there is no doubt in my mind that NTIP could be made to satisfy the
OLI requirements, It is my strong opinion that LMP should be the solution
chosen by the CCAMP working group due to the reasons outlined above.

Comments please!

Regards,
Andre