RSVP (Cont.)
When an application requests a specific quality for its data stream, the host computer system uses RSVP to deliver (cascade) the request to all routers on the stream’s path, all the way to the destination, and maintain the router and host state that is necessary to provide the service.
When all routers and the destination agree to honor the request (by squeezing other “best effort” i.e. ABR streams), the application can proceed.