RSVP (Resource Reservation Protocol)
Typically all IP traffic on the Internet is delivered on a best-effort basis. This delivery method does not address the requirements of multimedia applications such as videoconferencing, real-time IP multicasting and Internet telephony. RSVP is an effort to address the performance needs of such applications.
RSVP is a signaling and control protocol that doesn't carry application data. It operates on top of IP in the transport layer of the OSI protocol stack.
Host applications use RSVP to request the necessary QoS (such as guaranteed bandwidth) from the network for specific data flows. The QoS request is sent through all the routers along the path of the data flow on a hop-by-hop basis, and at each device the RSVP process attempts to establish and maintain a reservation state to provide the requested service.
Refresh messages are sent periodically by hosts and routers to maintain this state during the duration of the data transfer. The established state ends when the end host sends an explicit "teardown" message after the application has finished sending the data. RSVP also adapts to routing topology and multicast group membership changes.
From RSVP provides quality of service, Network World Tech Update, 06/17/02.
Additional resources
RSVP Protocol Overview
A quick overview of the protocol from the USC Information Sciences Institute.
IETF RSVP working group
Add a comment
Network World on Twitter: Get our tweets and stay plugged in to networking news
