The MPLS WG Archive

[Eric Gray <eric.gray@sandburst.com>]

Paul,

    Any references to bi-directional LSP establishment that
might have appeared in the architecture or applicability in
in the MPLS working group would have been either an
exceptionally insightful forward references, or wrong.  :-)

    Dmitry refers to relatively new work.

--
Eric Gray

You wrote:

> Dmitri,
>
> Where is that stated? I've checked in the MPLS Architecture documents,
> searching with the "bidirectional" and "bi-directional" keywords, and I
> haven't been able to find it mentioned.
>
> On the other hand, the two applicability documents for CR-LDP and RSVP-TE both
> state that bi-directional LSP set up is not yet supported:
>
> Applicability Statement for CR-LDP (13805 bytes):
>     "CR-LDP specification only supports unidirectional LSP setup.
> Bi-directional LSP setup is FFS."
>
> Applicability Statement for Extensions to RSVP for LSP-Tunnels (16573 bytes):
>     "The RSVP-TE specification supports only unidirectional LSP- tunnels.
> Bidirectional LSP-tunnels are not supported."
>
> Many thanks,
> Paul
>
> PS Thanks Jane for the response.
>
>  Dmitri Ryumkin wrote:
>
> > Paul,
> >
> > Generalized MPLS defines procedures for bi-directional LSP setup.
> >
> > Regards,
> > Dmitry Ryumkin
> >
> >  -----Original Message-----
> > From:   djiang1@lucent.com [mailto:djiang1@lucent.com]
> > Sent:   Monday, February 26, 2001 8:52 AM
> > To:     Paul Moore
> > Cc:     mpls@UU.NET
> > Subject:        Re: MPLS LSPs and ATM PVCs
> >
> > HI Paul,
> >
> > I believe RSVP is never intended to set up two LSPs using one single
> > operation.  We will have to use two RSVP signalling operations to set up
> > the two LSPs, one for each direction, even if the PVC may be used
> > bidirectionally.
> >
> > Regards,
> > Jane D. Jiang
> >
> > Paul Moore <paul-patrick.moore@alcatel.be>@UU.NET on 02/26/2001 08:11:29 AM
> >
> > Sent by:  owner-mpls@UU.NET
> >
> > To:   mpls@UU.NET
> > cc:
> > Subject:  MPLS LSPs and ATM PVCs
> >
> > Hello,
> >
> > I have a question about MPLS and ATM. ATM point-to-point PVCs can be
> > either uni-directional or bi-directional. MPLS LSPs are only
> > uni-directional. Is there any work being done concerning bi-directional
> > LSPs, for example, to allow two LSPs to be established by a single RSVP
> > signalling operation?
> >
> > I've just joined the list, so apologies if this has already been
> > discussed.
> >
> > Thanks,
> > Paul
> >
> > --
> > Paul Moore
> > Alcatel Bell
> > +32 3 450 3536
> > paul-patrick.moore@alcatel.be
>
> --
> Paul Moore, ext 53536
> paul-patrick.moore@alcatel.be
> Alcatel Bell
> 03/450.3536