Subject: RSVP tear down from intermediate node

From: "Pietro Tou" <[email-masked]>
Date: Thu, 13 Jun 2002 15:26:22 +0200

Hi all
we have a question: how can we force RSVP to tear down an LSP from an 
intermediate node? 

We thought about triggering a Resv Err message from the intermediate node to 
the destination node of the LPS to be torn down. In fact, Resv Error message 
is used to notify preemption (according to RFC), but how can the message be sent?  
Is there a way to make the "administrative preemption"?
RAPI calls seem to not cover this request, because all error messages seem to 
be managed only internally in the RSVP daemon.

I hope someone can help!!
Pietro Tou

---

From: David Charlap <[email-masked]>
Date: Thu, 13 Jun 2002 09:59:01 -0400

Pietro Tou wrote:
> 
> we have a question: how can we force RSVP to tear down an LSP from
> an intermediate node?

You can't.  It can send a PathErr to the ingress node.  Depending on the
kind of error you send, the ingress node should respond by tearing the
LSP.

> We thought about triggering a Resv Err message from the
> intermediate node to the destination node of the LPS to be torn
> down.

ResvErr won't help, because the egress node is not the node that must do
the actual tear.

> In fact, Resv Error message is used to notify preemption
> (according to RFC), but how can the message be sent?

ResvErr is used for many things.

And preemption should cause _both_ a PathErr and ResvErr to be
generated.

> RAPI calls seem to not cover this request, because all error
> messages seem to be managed only internally in the RSVP daemon.

If there isn't an error code/value that describes exactly what you want,
pick one that comes close.  If you want to define a new one, write a
draft and submit it here for us to discuss.

-- David