Resource Reservation Protocol (RSVP) is a signalling technique used to guarantee quality of service (QoS) by reserving bandwidth for RSVP-capable data flows. Typical applications would be video and audio streaming between servers or between a server and a specific PC, such as a demonstration PC in a conference room. All PCs in the data path must be RSVP compliant for a guaranteed QoS – ie. they must all have RSVP running, which instantly eliminates Win9x/ME/NT4 PCs. A typical reservation flow is initiated by sending a PATH message downstream to the receiver. Each PC in the data path establishes a PATH state, to maintain the appropriate QoS. A PATH message states the flow ID, reservation information, and the source and destination address. Once the PATH message reaches the destination PC, the request is handled by the local RSVP process, RSVP.EXE, which processes the request for validity in terms of whether it has the available resources to satisfy the request and whether the originator has permission to make the request in the first place. The RSVP process then either sends back an error response to the sender, or the appropriate QoS is implemented. A RESV message is then sent upstream from the receiver to each PC in the reverse data path. The RESV message uses the same flow information used in the PATH message. Routers along the path commit to the reservation and then store the information in a flow table. This process is repeated until the sender gets the RESV message. The reservation is then set up. Once the sender and receiver have completed their intended tasks with the reserved data flow, a PathTear message is sent to break the guaranteed bandwidth connection. At that point resources are then released by all PCs in the bandwidth path so they can be used in a later reservation.
Unless this service has been set up by your Network Administrator, you do not need to have it running. Similarly, if this PC is not on a network, you definitely do not need this service running. If you are on a network, consult therefore with your Network Administrator, otherwise disable this service by setting the RSVP service to Manual in “Control Panel \ Administrative Tools \ Services”.
If you're not sure about a process another way you can check is searching for the file (the executable; name of the process) on your computer, then checking its properties. If the description or company name is missing or sounds strange it's probably spyware/adware/virus. Windows files (and most other legitimate files) usually have full descriptions, as well as the company name.
The properties of the file in question, RSVP.EXE shows "Microsoft RSVP" and is copyrighted by "Microsoft Corporation", meaning that it's probably a valid Windows file (and it is, as Lento has shown).