Subject: MPLS and Optical network!!

From: "Sheng-hung Shih" <[email-masked]>
Date: Mon, 24 Jan 2000 11:45:31 +0800

Hi all:
     I'm a master student and a rookie in the MPLS related field.I'm doing
some research about MPLS and optical network.As the draft presented,MPLS can
be combined with OXCs.But how can optical trails be labeled?And if we want
to do explicit routing,how can we do push and pop toward the optical data
trail?
Thank you very much!!

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From: Jeremy Lawrence <[email-masked]>
Date: Mon, 24 Jan 2000 15:12:06 +1100

Sheng-Hung,

At 11:45 01/24/2000 +0800, Sheng-hung Shih wrote:
>be combined with OXCs.But how can optical trails be labeled?

On an ATM network, each link supports many different virtual circuits,
and ATM MPLS treats each VCI on a link as a distinct label.

Similarly, in an OXC network, each link supports many lightpaths, and
MPLS (as proposed for OXCs) treats each lightpath wavelength on a link
as a distinct label.

>And if we want

In ATM MPLS network, the top-level label on a packet is applied by
sending the packet on a virtual circuit with a chosen VCI. Similarly,
in optical MPLS, the top-level label will be applied to a packet by
sending it on a lightpath with a chosen wavelength.

Hope this helps,

Jeremy Lawrence

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From: "Sheng-hung Shih" <[email-masked]>
Date: Mon, 24 Jan 2000 14:12:52 +0800

> sending it on a lightpath with a chosen wavelength.
   It seems like the hop-by-hop routing,isn't it?And the number of
wavelength is also a problem.

Sheng-hung Shih

---

From: Jeremy Lawrence <[email-masked]>
Date: Mon, 24 Jan 2000 17:16:41 +1100

At 14:12 01/24/2000 +0800, Sheng-hung Shih wrote:
>    It seems like the hop-by-hop routing,isn't it?

The intended use of optical MPLS is not hop-by-hop routed MPLS,
but explicitly routed MPLS.

>And the number of

Well, 80 wavelengths is enough for one router to connect to 80
others across an OXC network (subject to a valid route being
available for each lightpath), so this isn't too much of a problem.
There are rumours of OXCs coming which support 1000+ wavelengths.

Regards,

Jeremy Lawrence