The Resource Reservation Protocol (RSVP) is a network control protocol used by a host to request specific qualities of service from the network for particular application data streams or flows. RSVP is also used by routers to deliver quality of service (QoS) requests to all nodes along the paths of the flows and to establish and maintain operational state to provide the requested service. In general, RSVP requests result in resources reserved in each node along the data path.
The Resource Reservation Protocol for Traffic Engineering (RSVP-TE) is an extended version of RSVP for MPLS. RSVP-TE uses traffic engineering extensions to support automatic signaling of LSPs. MPLS uses RSVP-TE to set up traffic-engineered LSPs. See RSVP-TE Extensions for MPLS for more information.