Resource Reservation Protocol

The Resource Reservation Protocol (RSVP) is a Transport Layer protocol designed to reserve resources across a network for an integrated services Internet. RSVP operates over an IPv4 or IPv6 Internet Layer and provides receiver-initiated setup of resource reservations for multicast or unicast data flows with scaling and robustness. It does not transport application data but is similar to a control protocol, like Internet Control Message Protocol (ICMP) or Internet Group Management Protocol (IGMP). RSVP is described in RFC 2205.

RSVP can be used by either hosts or routers to request or deliver specific levels of quality of service (QoS) for application data streams or flows. RSVP defines how applications place reservations and how they can relinquish the reserved resources once the need for them has ended. RSVP operation will generally result in resources being reserved in each node along a path.

RSVP is not a routing protocol and was designed to inter-operate with current and future routing protocols.

RSVP by itself is rarely deployed in telecommunications networks today but the traffic engineering extension of RSVP, or RSVP-TE, is becoming more widely accepted nowadays in many QoS-oriented networks. Next Steps in Signaling (NSIS) is a replacement for RSVP.