Router Interface; Choosing The Signaling Protocol - Alcatel-Lucent 7450 Manual

Router Interface

At least one router interface and one system interface must be defined in the
config>router>interface context in order to configure MPLS on an interface.

Choosing the Signaling Protocol

In order to configure a static or a RSVP signaled LSP, you must enable MPLS on the router
which automatically enables RSVP and adds automatically the system interface into both
contexts. Any other network IP interface, other than loopbacks, added to MPLS is also
automatically enabled in RSVP and becomes a TE link.When the interface is enabled in
RSVP, the IGP instance will advertise the Traffic Engineering (TE) information for the link to
other routers in the network in order to build their TE database and compute CSPF paths.
Operators must enable the traffic-engineering option in the ISIS or OSPF instance for this.
Operators can also configure under the RSVP context of the interface the RSVP protocol
parameters for that interface.
If only static label switched paths are used in your configurations, then operators must
manually define the paths through the MPLS network. Label mappings and actions configured
at each hop must be specified. Operators can disable RSVP on the interface if it is used only
for incoming or outgoing static LSP label by shutting down the interface in the RSVP context.
The latter causes IGP to withdraw the TE link from its advertisement which removes it from
its local and neighbors TE database.
If dynamic LSP signaling is implemented in an operator's network then they must keep RSVP
enabled on the interfaces they want to use for explicitly defined or CSPF calculated LSP path.
7450 ESS MPLS Guide
MPLS and RSVP
Page 173