Subject: RSVP Path Message - Sender Descriptor

From: Rajesh P Jain <[email-masked]>
Date: Tue, 05 Jun 2001 13:08:43 +0530

"Hi",
                        With reference to RFC 2205, PATH Message
contains "Sender Descriptor" parameter as an "Optional Object".

                        Why is the "Sender Descriptor"
(<SENDER_TEMPLATE> <SENDER_TSPEC> [<ADSPEC>]), Optional????

                            If it is optional, How are Path States
created without SENDER_TEMPLATE???? (Since the section 3.1.3 of RFC 2205
says that "Each RSVP-capable node along the path(s) captures a path
message and processes it to create path state for the sender defined by
the SENDER_TEMPLATE and SESSION objects).

                            Please throw light on the above statement of
the RFC???

TIA,

                Rajesh P Jain

---

From: David Charlap <[email-masked]>
Date: Wed, 06 Jun 2001 10:57:29 -0400

Rajesh P Jain wrote:
> 
> With reference to RFC 2205, PATH Message contains "Sender
> Descriptor" parameter as an "Optional Object".
> 
> If it is optional, How are Path States created without
> SENDER_TEMPLATE???? (Since the section 3.1.3 of RFC 2205 says that
> "Each RSVP-capable node along the path(s) captures a path message
> and processes it to create path state for the sender defined by

The RSVP-TE draft (draft-ietf-mpls-rsvp-lsp-tunnel-08) does not have
sender descriptor as an optional object, so the question is moot for
MPLS.

With respect to why RFC-2205 declares sender optional, the only thing I
can think of is that is may not be necessary if WF-style reservations
are used.  You may find the RSVP working group more helpful here.  Here
are it's home pages: 
	http://www.ietf.org/html.charters/rsvp-charter.html
	http://www.isi.edu/div7/rsvp/rsvp.html

-- David