The MPLS WG Archive

[David Charlap <David.Charlap@marconi.com>]

Bin Zhou wrote:
> 
> But I really need to provide a host address in the PATH message.
> How to avoid using the extended tunnel ID?
> Otherwise, I want to define a new field, named Tunnel Client
> Address in the
> Session object.

Your sender address is part of the SENDER_TEMPLATE object.  That's where
you should get it from.  That field has to be a valid IP address, and
should be an address that corresponds to the ingress router.

In a Resv message, this same address will be part of the FILTER_SPEC
object.

You can use a zero for extended tunnel ID, if you like, but you run the
very real risk of sharing your reservations with a completely unrelated
LSP if you do this.

It's really not a big deal to copy your sender address into the extended
tunnel ID as well.

What, exactly is the problem you're having?

If you believe that the sender address in the SENDER_TEMPLATE changes as
the Path message is propagated, you are wrong.  (If you don't believe
this, I apologize for jumping to conclusions, but I have seen people
with this mistaken impression.)  The SENDER_TEMPLATE is an invariant,
just like the SESSION object is.  The sender address contained within it
will always be the address that was assigned to it by the ingress node.

-- David