The MPLS WG Archive

[Lou Berger <lberger@labn.net>]

At 07:51 AM 9/29/00, Adrian Farrel wrote:
> >>Note that whether intermediate nodes process the message is a
> >>distinct issue from whether the message traces the LSP
> >>hop-by-hop or goes along a completely different path.
> >
> >Care to elaborate on the importance of this issue?
>
>Lou,
>I just want to separate the discussions.
>
>I don't think it is a big deal if every LSR on the path of a Notify passes
>the message through software.  I just think it a shame not to offer the
>facility for a switch to fast-path the message (i.e. not remove it from
>forwarding hardware) if it is capable.  Thus I would be happy with Notify
>targeted at some remote node and router alert NOT set.  It is then up to the
>individual switch how optimally it processes the packets.
>
>I believe it is important to allow a Notify to not retrace the path of the
>LSP.  This allows a Notify to be routed around a fialure (2nd order failure
>- so perhaps not too important).  It also allows a Notify to be sent to some
>other entirely distinct node (widening the purpose of Notify from simple
>protection switching).

Why is this important?  If there's such a failure, the node upstream of the 
failure can (and should) generate the error (and Notify).

Lou

>Adrian