[mpls] My question about "static LSP" in TEAS today

"Adrian Farrel" <adrian@olddog.co.uk> Tue, 05 April 2016 21:40 UTC

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From: Adrian Farrel <adrian@olddog.co.uk>
To: "'Tarek Saad (tsaad)'" <tsaad@cisco.com>
Date: Tue, 05 Apr 2016 22:40:24 +0100
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Subject: [mpls] My question about "static LSP" in TEAS today
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I probably wasn't clear in my question. To restate, my question is why is the
static LSP model modelling an end-to-end LSP and not just a single "cross
connect"? Alternatively, what is the difference between an LSP provisioned by a
control plane, and an LSP provisioned by the management plane? And we might even
bring in "soft permanent LSPs" that are a stitching together of some static
segments and some dynamic segments.

(You might look at the LSR MIB module that can be used to provision [aka model]
static LSPs.)

When you model maybe you need to think about what is the purpose of modelling.
There are three things going on:

What is the user/application asking for?
What state is held in the network?
What does the data plane have?

In this case there is no control plane, but there is still distributed state
installed in the network.
You said that this is not a data plane model, which is fine.
So you are modelling either the state in the network or the user's request.
Now, there may be protocol state (such as parameters of RSVP-TE that exist to
keep the protocol on side) that are special, but the parameters that describe
the state that applies to the LSP are surely identical regardless of how the LSP
was set up. That is, the LSP is a sequence interfaces and labels as well as some
information about reserved resources. 

I think I'm rambling. What I am trying to say is that an LSP is an LSP.