Resource Reservation Protocol (RSVP)

Resource Reservation Protocol is the protocol used to avoid congestion in the network. The resource being used will be available based on this protocol mechanisms.

Here’s an example of how RSVP works. Let’s first look at what the problem would be without RSVP.

In this example, the video traffic still gets through, but it is impacted by a large file transfer in progress. This causes a negative effect on the quality of the video and the picture comes out all delay.

What we need is a method to reserve bandwidth from end-to-end on a per-application basis. RSVP can do this.

This figure explains how RSVP actually works.RSVP reserves bandwidth from end-to-end on a per-application basis for each user.

This is especially important for delay-sensitive applications, such as video.

As shown here, with RSVP, the client’s application requests bandwidth be reserved at each of the network elements on the path. These elements will reserve the requested bandwidth using priority and queuing mechanisms.

Once the server receives the OK, bandwidth has been reserved across the whole path, and the video stream can start being transmitted. RSVP ensures clear video reception.

The good news is that RSVP is becoming widely accepted by industry leaders, such as Microsoft and Intel, who are implementing RSVP support in their applications.