Subject: Sender TSpec on PathTear

From: Adrian Farrel <[email-masked]>
Date: Mon, 20 Mar 2000 12:32:03 -0000

All,

RFC 2205 states that Sender TSpec is mandatory on a PathTear
if a Sender Descriptor is included.

    <PathTear Message> ::= <Common Header> [ <INTEGRITY> ]
                           <SESSION> <RSVP_HOP>
                           [ <sender descriptor> ]

    <sender descriptor> ::= (see earlier definition)

Where the earlier definition of sender Descriptor is found in
the definition of Path Message and is...

    <sender descriptor> ::= <SENDER_TEMPLATE> <SENDER_TSPEC>
                            [ <ADSPEC> ]

draft-ietf-mpls-rsvp-lsp-tunnel-05 does not make any change to 
this requirement, but does add [RECORD_ROUTE] as an optional
field in Sender Descriptor.

It seems to me that SENDER_TSPEC, ADSPEC and RECORD_ROUTE do
not add anything to PathTear.

Can anyone comment on whether or not it would be better to 
define PathTear as

    <PathTear Message> ::= <Common Header> [ <INTEGRITY> ]
                           <SESSION> <RSVP_HOP>
                           [<SENDER_TEMPLATE>]

Of course the effect of this can be mitigated by applying the
usual rules of conservative on send, liberal on receive.

Regards,
Adrian
--
Adrian Farrel  mailto:[email-masked]
Network Convergence Group
Data Connection Ltd., Chester, UK
http://www.datcon.co.uk/
Tel: +44 (0) 1244 313440  Fax: +44 (0) 1244 312422