RSVP is a transport layer protocol that is used to reserve resources in a computer network to get different quality of services (QoS) while accessing Internet applications. It operates over Internet protocol (IP) and initiates resource reservations from the receiver’s end.
RSVP is a receiver oriented signalling protocol. The receiver initiates and maintains resource reservation.
It is used both for unicasting (sending data from one source to one destination) and multicasting (sending data simultaneously to a group of destination computers).
RSVP supports dynamic automatic adaptation to changes in network.
It provides a number of reservation styles. It also provides support for addition of future styles.
There are two types of RSVP messages −
Path Messages (path): A path message is sent by the sender to all receivers by multicasting storing the path state at each node in its path. It stores the necessary information so that the receivers can make the reservation.
Reservation messages (resv): The resv message is sent by the receiver to the sender along the reverse path of the path message. It identifies the resources that is requires by the data flow.