The MPLS WG Archive

[Bala Rajagopalan <braja@tellium.com>]

Hello:

The problem is exactly as you describe:   clear requirements
to my knowledge, have not emerged from service providers regarding
services at the IP-optical interface. The OIF and ODSI have
assumed  certain service definitions, based on a common-sense
approach covering functionality that is assumed minimally required.
The UNI functionality being defined are based on
these service definitions. Presently, these service definitions do
not require external IP routers to "control" the optical network.
If these service definitions change, then the type and amount of
information
exchange required at the service interface would also change.
The OIF has initiated a task group of carrier representatives to examine
this issue.

It's clearly necessary to get the carrier input into the standardization
process in this area, wherever it occurs (including IETF). Given that many
new
developments have occured in a short time, the carriers may be more
focussed on managing an optical network internally, rather than worry
about the interface definitions. But life goes on in various forums
regardless!

Regards,

Bala





Mark Jones wrote:

> Only time will be able to answer these questions.
>
> Here's one perspective from a person who claims some expertise in
> optical networking.  Hopefully, the industry will settle on a common
> control plane to facilitate messaging between layers, but one layer is
> unlikely to have full control of another.  Small homogeneous networks
> may be the exceptions.  There are too many complexities in network
> management of different layers to expect multiple layers to collapse
> under one control plane (though the protocols in each may be the same).
>
> The ODSI and OIF may define just such an interface, but unless carriers
> accept it as a reasonable solution to management of their networks, it
> won't be implemented on a large scale.  The ODSI and OIF have both been
> anxious to show quick results, regardless of whether they met the
> requirements of major customers.  I don't want to be too critical here,
> because the ODSI and OIF output may be exactly what we need in our
> networks, but the lack of rigor in development of their specifications
> concerns me.  The OIF has jumped to solutions from the beginning,
> without creating clear requirements for what network providers needed.
> So, issues like whether carriers wanted an IP router to be able to
> fully control an optical cross connect have been ignored.  (Sprint has
> not participated in the ODSI as far as I know.)
>
> The two camps on this issue, even within Sprint, fall into those who
> love IP and those who only accept it as the primary growth protocol
> today.  The IP lovers want IP routers to have flexibility to fully
> control the optical network.  The other group is concerned by the
> history of router failures, IP's limited and complex traffic
> engineering, and the many other protocols that must be supported on a
> common transport infrastructure.  The decision of whether IP routers
> will have the ability to control an optical network may come down to a
> political decision as much as an economic or technical one.
>
> Mark Loyd Jones
> Sprint
> Technology Planning & Integration
> 913-534-5247
> mark.jones@mail.sprint.com
>
> -----Original Message-----
> From: clapp [mailto:clapp@research.telcordia.com]
> Sent: Thursday, June 15, 2000 2:25 PM
> To: tli
> Cc: clapp; mpls
> Subject: FW: RE: Information about optical routing in MPLS net.
>
> I agree with the notion of optical equipment reusing IP control
> protocols
> to manage the network, but to what extent will routers that are clients
> of
> an optical network manage that network?  The ODSI is defining an
> interface
> (using MPLS signaling protocols) to enable a router to manage an
> optical
> channel, and they say that ATM switches and SONET ADMs can do the same.
>
> Managing a channel isn't the same thing as managing a network, but it's
> a
> beginning.  How far do people think it will go?
>
> George Clapp
> voice     973-829-4610
> email     clapp@research.telcordia.com
>
> At 11:28 AM 6/15/00 -0700, you wrote:
>
> >  | I would support the view that having the router control the
> optical domain
> >  | is not good.  This comes down to a simple desire to see an optical
> layer
> >  | which is open to ALL clients - not just IP.  Of course it is
> possible to
> >  | allow the router to control the optical layer ... however, this
> idea
> >  | overlooks the fact that an operator may wish to carry many other
> clients
> >  | across an optical network.
> >
> >
> >The optical plane clearly needs a control plane that provides a
> (lambda)
> >routing and signaling infrastructure.  This infrastructure is
> fundamentally
> >similar to the routing and signaling technology that we're already
> using
> >for MPLS.  Now, we can choose to re-invent this technology, or we can
> >leverage the technology that we have already have developed and have
> >started to deploy.
> >
> >Note that this argument is completely independent of the nature of the
> >optical client.  Nothing here precludes non-IP usage of the optical
> core.
> >It would simply use the IP network as the out-of-band control plane.
> >
> >Regards,
> >Tony

--

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