The MPLS WG Archive

["Feng, Mark" <m_feng@trillium.com>]

I have some doubts on the expected behavior of the egress router regarding
the handling of the following scenario.

   If the newly added subobject causes the RRO to be too big to fit in a
   Path (or Resv) message, the RRO object SHALL be dropped from the
   message and message processing continues as normal.  A PathErr (or
   ResvErr) message SHOULD be sent back to the sender (or receiver).  An
   error code of "Notify" and an error value of "RRO too large for MTU"
   is used.  If the receiver receives such a ResvErr, it SHOULD send a
   PathErr message with error code of "Notify" and an error value of
   "RRO notification".

When the egress router receives the ResvErr, should it remove the RRO
objects from the Resv message? The problem is that, before the PathErr
reaches the ingress router, subsequent refresh Path message will still have
the RRO object present.

IMO, the egress router should not remove the RRO. When the ingress router
receives the PathErr message, it will remove the RROs in the Path message,
which will trigger the removal of the RRO objects in the corresponding Resv
message.

I would appreciate any comments regarding this.

Thanks in advance.

- Mark