Subject: RFC3209 Section 4.1.2

From: "Hong Liao" <[email-masked]>
Date: Thu, 25 Jul 2002 11:18:24 -0400

Hi,

In RFC3209 Section 4.21.2 non-support of the label object.

4.1.2. Non-support of the Label Object

   Under normal circumstances, a node should never receive a LABEL
   object in a Resv message unless it had included a LABEL_REQUEST
   object in the corresponding Path message.  However, an RSVP router
   that does not recognize the LABEL object sends a ResvErr with the
   error code "Unknown object class" toward the receiver.  This causes
   the reservation to fail.

For example,

A  -------LSR--------B

If the A sent out a Path msg without the LRO, LSR will forward this path
msg to B, then if B sent a Resv msg with a Label object, will the LSR send
the Resverr msg with the error code "Unknown object class" toward B?

I do think so unless LSR is non-support the LABEL object.

Please let me know if it is correct.

Thanks in an advance.

Julia

---

From: David Charlap <[email-masked]>
Date: Thu, 25 Jul 2002 11:41:30 -0400

> the Resverr msg with the error code "Unknown object class" toward B?

If A didn't send a LABEL_REQUEST, and B sent back a LABEL anyway, then B 
is broken.

No LSP can possibly come up, because A wasn't trying to establish one in 
the first place.  It is absolutely correct for A to generate a ResvErr.

> I do think so unless LSR is non-support the LABEL object.

If A generated a Path without a LABEL_REQUEST, then either it is not 
running RSVP-TE (meaning the LABEL object definitely isn't supported), 
or it is a hybrid router, running both classical RSVP and RSVP-TE at once.

If it is such a hybrid, then the decision of what to do with an 
unexpected LABEL object is not specified.  Personally, I think the 
ResvErr should still be generated, since that's what a non-TE router 
would do for the exact same session.

-- David