Subject: LSP life time

From: "Faisal S. Naik" <[email-masked]>
Date: Fri, 24 Nov 2000 00:03:29 +0500

What is the lifetime of an LSP?
What is the number of tunnels that can be created within an LSP.
Regards,
---------
Faisal S. Naik
Senior Network Engineer,
Hamdard Education Network,
Hamdard University,
Karachi.
Ph: (92)-021-4383986-7

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From: Jeremy Lawrence <[email-masked]>
Date: Fri, 24 Nov 2000 09:51:35 +1100

>What is the lifetime of an LSP?

A hop-by-hop routed LSP will exist without change for as long as
there is no change in the route for the FEC for which it is established.
In an ideal network which never experiences routing changes, the
hop-by-hop routed LSPs' lifetimes will be infinite.

A traffic engineering LSP will exist without change for as long as
there is no significant change in link loading, or other routing
state, which would affect the routing of the LSP.

Other uses of LSPs are possible, and some of those might involve
more frequent changes or set-ups of LSPs.

>What is the number of tunnels that can be created within an LSP.

It is effectively unlimited. If a single extra level of labelling
is used inside the LSP, 1M LSPs can be carried inside an LSP.
However, labels can be stacked to an arbitrary number of levels,
so an arbitrary number of LSPs can be carried inside an LSP.

(It is also possible to use other types of tunnels, e.g. IPSec
or GRE, inside an LSP.)

Jeremy Lawrence

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From: David Charlap <[email-masked]>
Date: Mon, 27 Nov 2000 11:47:49 -0500

> is used inside the LSP, 1M LSPs can be carried inside an LSP.

Possibly more than that, depending on what kind of links the LSP is
traversing.  The 20-bit label size is the generalized label used when
sending labeled traffic over packet-oriented links (like POS).

When sending over connection-oriented links (like ATM or frame relay),
the label is the link's connection identifier (VPI/VCI or DLCI), and its
range is subject to the restrictions imposed by that technology.  This
range may be larger than 20 bits.

-- David