Subject: Information about optical routing in MPLS net.

From: Alessandro Bosco <[email-masked]>
Date: Wed, 14 Jun 2000 15:54:23 +0200

Dear Sir/Madam,

I have some questions about routing within an optical MPLS networks
(MPLS/MPL(ambda)S).

In the draft "Multi-Protocol Lambda Switching: Combining MPLS Traffic
Engineering Control With Optical Cross-connects", it is affirmed the
following phrase:

" The proposed OXC control plane uses the IGP extensions for MPLS
traffic engineering to distribute relevant optical transport network
state information, including topology state information. This state
information is subsequently used by a constraint-based routing system to
compute paths for point-to-point optical channels through the optical
transport network."

I would like to know if:

a. Considering explicit paths calculation through an optical MPLS
network, ingress
    routers or third part tools, at the input of the network, will still
calculate the
    entire path (ingress to egress router), considering links within the
optical domain
    too?

b. Or, "new" OXCs, that use a control plane extended from MPLS traffic
    engineering control module, will be able to do optical routing, I
mean optical path
    calculation at the input of optical domain?

c. In the MPL(ambda)s framework, "new" OXCs has to be seen like optical
    routers?

Any response will be very appreciated.

Thanks in advance.

Best regards.

Alessandro

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From: Yangguang Xu <[email-masked]>
Date: Wed, 14 Jun 2000 11:26:00 -0400

>     entire path (ingress to egress router), considering links within the

There have been discussions about this before. My personal opinion is that
having router control optical domain is not feasible both technically and
practically. 

>     calculation at the input of optical domain?

This is what I support. Optical path can be set up either through topology
driven, real-time traffic driven or traffic pattern driven. There have to be
extra functions and intelligence at the intersection of data domain and optical
domain. ODSI addresses some issues already. I am now thinking how COPS could be
extended to apply here. Any people interested in this topic?

> c. In the MPL(ambda)s framework, "new" OXCs has to be seen like optical

If you mean optical router as optical packet router, then I don't think so.

Yangguang

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From: Bala Rajagopalan <[email-masked]>
Date: Thu, 15 Jun 2000 11:43:40 -0400

There is a draft that describes some of the routing choices for IP over optical.
Please see  http://www.ietf.org/internet-drafts/draft-prs-optical-routing-00.ps

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: [email-masked]

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From: George Clapp <[email-masked]>
Date: Thu, 15 Jun 2000 12:09:19 -0400

>having router control optical domain is not feasible both technically and

Could you give some examples of why it's not feasible?

Thanks,
George Clapp
voice     973-829-4610
email     [email-masked]