The MPLS WG Archive

[Eric Gray <EGray@zaffire.com>]

Eric (et al),

    Tom earlier made the point that none of the
MPLS drafts appear to introduce - let alone 
discuss or specify - the notion of bi-directional
association of LSPs.  There is the notion of use
of Labels under circumstances in which specific
hardware uses "labels" (VPI/VCI, and possibly
DLCI, values) in both directions, but this is not
the same thing.

    In an off-line discussion, we talked about the
fact that the TE Requirements RFC (RFC2702) talks 
about the idea of bi-directional traffic trunks.  
It describes behaviors which might be hard for an 
NMS to model without being able to determine that 
an LSP-pair is used as a bidirectional LSP tunnel.
But it is "only" an informational RFC.

	The Framework draft briefly mentions use of
bi-directional LSPs as a possible solution to error
reporting problems, but - as far as I know - none
of the current set of "standards track" MPLS drafts
addresses the concept of pairing of LSPs to form a
bi-directional tunnel or trunk.

	Is it possible to add this to the Architecture
at this point, do we need to create a standards track
draft specifically for this purpose or is it enough 
to simply add appropriate "stuff" to the TE-MIB based
on the informational RFC?

--
Eric Gray