The MPLS WG Archive

[Sid Chaudhuri <sc@tellium.com>]

I don't see why TE and protection require the routers to specify explicit
routes.
The routers can simply specify to the optical layer what type of optical
layer protection
it requires.  Based on its traffic flow a router only needs to know between
which
two routers it needs to establish a new lightpath.  How the lightpath is
routed in the
optical layer seems to me irrelevant to TE.

Sid Chaudhuri


		-----Original Message-----
		From:	Kireeti Kompella [mailto:kireeti@juniper.net]
		Sent:	Monday, October 23, 2000 11:43 AM
		To:	xuyg@lucent.com; yxue@UU.NET
		Cc:	ip-optical@lists.bell-labs.com; mpls@UU.NET
		Subject:	Re: [IP-Optical] RE: Optical link bundling.
Was Re: DraftMinutes From         Pittsburgh

		Hi,

		> > (router determines the explicit routes). 
		> 
		> This point has been raised by several folks. It really
confuses me. If the
		> optical switches are equipped with path calculation
ability, what's the benefit
		> to bother router to determine the explicit routes within
optical domain
		> (assuming router can be smart enough to handle all optical
network specific
		> attributes and constrains) than just have routers to
determine the end points of
		> optical trails.

		Why does this confuse you?  Routers may want to determine
the exact
		path that their LSPs take for a number of reasons, including
TE and
		protection.  If a router doesn't care where its LSPs are
laid out,
		it can install loose hops at the boundaries of the optical
cloud.

		Kireeti.