actually Resource Reservation Protocol or route reservation in internetworks (RSVP) is a network-control protocol that enables Internet applications to obtain differing qualities of service (QoS) for their data flows. Such a capability recognizes that different applications have different network performance requirements. Some applications, including the more traditional interactive and batch applications, require reliable delivery of data but do not impose any stringent requirements for the timeliness of delivery. Newer application types, including videoconferencing, IP telephony, and other forms of multimedia communications require almost the exact opposite: Data delivery must be timely but not necessarily reliable