Resource Reservation Protocol (RSVP) is used in real-time systems for an efficient quality band transmission to a particular receiver. It is generally used by the receiver side for the fast delivery of the transmission packets from the sender to the receiver.
Features of Resource Reservation Protocol:
- RSVP is receiver initiated. Receiver node in the real time system initiates the protocol.
- RSVP is simplex(unidirectional). The receiver node just receives the packets and does not want to send any data.
- Quality of Service is provided by RSVP protocol.
- Admission Control is used in RSVP at each hop in the network topology.
- Classification, buffer management, and scheduling is managed efficiently by RSVP
- It dynamically adapts to the change in route for the efficient message transfer.
- It is actually not a routing protocol. It depends upon other routing protocols.
Flowspec is used in RSVP to determines the different parameters like bandwidth, link strength, congestion, etc for smooth and collisionless communication and data transfer.
Filterspcec is used in RSVP for filtering of the packets. It is used to route the packets according to its destination type as a fixed or shared receiver.
Types of messages used in RSVP connection establishment:
- Reservation Message (resv): The receiver sends the Reservation Message (resv) to the sender, which specifies all the required resources and parameters for the reservation to establish.
- Path Message (path): Upon receiving the reservation message from the receiver, the sender records all the necessary resources to be reserved and records the path. The sender multicasts a Path Message (path) to all the receivers, which specifies the routing details of the packet. It also contains all the necessary specifications about the reservation to be made for the receiver.
Reservation Messages Transfer:
Path Messages Transfer:
The data sent by the sender in Resource Reservation Protocol is encrypted to prevent the data sent to the receiver from breach.
Error reporting is done at the sender side in Resource Reservation Protocol for making the necessary changes in the communication strategy.
In case of failure in RSVP, the admission state of the hop is sent to the requester for handling the necessary packets.
In RARP the routers record the necessary forward and reverse routing state. The router may also make the necessary changes in the path message sent by the sender to the receiver to indicate the actual resource availability.