The MPLS WG Archive

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

"Martin, Christian" wrote:
> 
> A device (router) cannot send PathErr if it doesn't speak RSVP.  In
> 2205, there is mention of Path messages passing through non-RSVP
> clouds.

And this is made illegal in the RSVP-TE draft.  See sections 4.2.5 and
4.5.

If an RSVP router has a non-RSVP downstream neighbor, it must not send a
Path message with a label-request object.  Instead, it should send a
PathErr message.  Similarly, if a router receives a Path message with
label-request from a non-RSVP router, it should send back a PathErr
message.

The draft specifies the presence of a label-request object, because this
is the primary mechanism for differentiating an RSVP Path message from
an RSVP-TE Path message.  Within any reasonable kind of MPLS cloud, all
Path messages will be RSVP-TE and will have label-request objects.

-- David