Feature Behavior - Alcatel-Lucent 7450 Manual

Automatic Creation of a RSVP Mesh LSP
Finally the auto-created mesh LSP can be signaled over both numbered and unnumbered RSVP
interfaces.

Feature Behavior

Whether the prefix list contains one or more specific /32 addresses or a range of addresses, an
external trigger is required to indicate to MPLS to instantiate an LSP to a node which address
matches an entry in the prefix list. The objective of the feature is to provide an automatic creation
of a mesh of RSVP LSP to achieve automatic tunneling of LDP-over-RSVP. The external trigger is
when the router with the router-id matching an address in the prefix list appears in the Traffic
Engineering database. In the latter case, the TE database provides the trigger to MPLS which
means this feature operates with CSPF LSP only.
Each instantiation of an LSP template results in RSVP signaling and installing state of a primary
path for the LSP to the destination router. The auto- LSP is installed in the Tunnel Table Manager
(TTM) and is available to applications such as LDP-over-RSVP, resolution of BGP label routes,
resolution of BGP, IGP, and static routes. The auto-LSP can also be used for auto-binding by a
VPRN service. The auto-LSP is however not available to be used in a provisioned SDP for explicit
binding by services. A consequence of this is that an auto-LSP can also not be used directly for
auto-binding of a PW template with the use-provisioned-sdp option in BGP-AD VPLS, or
FEC129 VLL service. However, an auto-binding of a PW template to an LDP LSP, which is then
tunneled over an RSVP auto-LSP is supported.
If the user changes the bandwidth parameter in the LSP template, an MBB is performed for all
LSPs using the template. If however the auto-bandwidth option was enabled in the template, the
bandwidth parameter change will be saved but will only take effect at the next time the LSP
bounces or is re-signaled.
Except for the MBB limitations to the configuration parameter change in the LSP template, MBB
procedures for manual and timer based re-signaling of the LSP, for TE Graceful Shutdown and for
soft pre-emption are supported.
Note that the use of the 'tools perform router mpls update-path' command with a mesh LSP is
not supported.
The one-to-one option under fast-reroute is also not supported.
If while the LSP is UP, with the bypass backup path activated or not, the TE database loses the
router-id, it will perform an update to MPLS module which will state router-id is no longer in TE
database. This will cause MPLS to tear down all mesh LSPs to this router-id. Note however that if
the destination router is not a neighbor of the ingress LER and the user shuts down the IGP
instance in the destination router, the router-id corresponding to the IGP instance will only be
deleted from the TE database in the ingress LER after the LSA/LSP ages out. If the user brought
back up the IGP instance before the LSA/LSP aged out, the ingress LER will delete and re-install
the same router-id at the receipt of the updated LSA/LSP. In other words, the RSVP LSPs destined
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