The MPLS WG Archive

[Hans Sjöstrand <hans@ipunplugged.com>]

The updated version of the MPLS-TC-MIB clarifies this.

           MplsLSPID ::= TEXTUAL-CONVENTION
              STATUS        current
              DESCRIPTION
                   "A unique identifier within an MPLS network that is
                    assigned to each LSP. This is assigned at the head
                    end of the LSP and can be used by all LSRs
                    to identify this LSP.  This value is piggybacked by
                    the signaling protocol when this LSP is signaled
                    within the network. This identifier can then be
                    used at each LSR to identify which labels are being
                    swapped to other labels for this LSP. This object
                    can also be used to disambiguate LSPs that
                    share the same RSVP sessions between the same
                    source and destination.

                    For LSPs established using CR-LDP, the LSPID is
                    composed of the ingress LSR Router ID (or any of
                    its own IPv4 addresses) and a locally unique
                    CR-LSP ID to that LSR. The first two bytes carry
                    the CR-LSPID, and the remaining 4 bytes carry
                    the Router ID. The LSPID is useful in network
                    management, in CR-LSP repair, and in using
                    an already established CR-LSP as a hop in an ER-TLV.

                    For LSPs signaled using RSVP-TE, the LSP ID is
                    defined as a 16-bit (2 byte) identifier used
                    in the SENDER_TEMPLATE and the FILTER_SPEC
                    that can be changed to allow a sender to
                    share resources with itself. The length of this
                    object should only be 2 or 6 bytes. If the length
                    of this octet string is 2 bytes, then it must
                    identify an RSVP-TE LSPID, or it is 6 bytes,
                    it must contain a CR-LDP LSPID."
              REFERENCE
                   "See [RFC3209] for RSVP-TE LSPID and [RFC3212] for
                    LSPID in CR-LDP."
              SYNTAX  OCTET STRING (SIZE (2|6))

A new draft is expected to be out within a few days. It's being revised 
in the IESG review process together with the other mibs being reviewed 
(LSP, TE, FTN, LDP).

Regards
/// Hasse

Haseeb Budhani wrote:
> I am having trouble understanding how the MplsLSPID for IPv4 end-points 
> ends up being 6 octets in this draft.
> 
> Any help will be appreciated.
>