Subject: Repost: Question re: P/NHOP in GMPLS

From: Michael Mandelberg <[email-masked]>
Date: Fri, 29 Aug 2003 23:52:36 -0400

According to rfc 3473, p. 22 :
 
A node that receives an IF_ID object SHOULD
   check whether the information carried in this object is consistent
   with the information carried in a received ERO, and if not it MUST
   send a PathErr Message with the error code "Routing Error" and error
   value of "Bad Explicit Route Object" toward the sender.  This check
   CANNOT be performed when the initial ERO subobject is not the
   incoming interface.
 
However, an LSR receiving a path message with an ero processes it as
follows: if the LSR is a part of the node specified by the first subobject,
it selects a hop, then *removes* that subobject. In other words, the ERO
does not contain information about the route to get to that LSR, this
information is in the RRO. 
 
This may be a minor point, but I want to make sure that I understand it
properly. Shouldn't the text above say:

A node that receives an IF_ID object SHOULD
   check whether the information carried in this object is consistent
   with the information carried in a received **RRO**, and if not it MUST
   send a PathErr Message with the error code "Routing Error" and error
   value of "Bad Explicit Route Object" toward the sender.  This check
   CANNOT be performed when the initial **RRO** subobject is not the
   incoming interface.
 
Am I mistaken? If so, why?
 
Thanks
 
Michael Mandelberg