Resource Reservation Protocol

Resource Reservation Protocol
Name	Resource Reservation Protocol
Abbreviation	RSVP
Initial release	1997
Developer	Internet Engineering Task Force
Status	Historic / Inactive for wide deployment
Os	Cross-platform
Genre	Network signaling protocol

Resource Reservation Protocol.

Resource Reservation Protocol is a network control protocol designed for reserving resources across an internetwork to support Quality of Service for multimedia and real-time applications. It was developed within the Internet Engineering Task Force and standardized in the late 1990s to enable end-to-end bandwidth reservation and delivery guarantees over packet-switched networks. RSVP interacts with routing protocols and transport mechanisms to signal reservation state and adapt to topology changes.

Overview

RSVP was specified by working groups in the Internet Engineering Task Force and documented in key RFCs to complement efforts by projects such as Integrated Services and Differentiated Services. The protocol sought to provide per-flow signalling capabilities to support applications developed in research initiatives at institutions like Carnegie Mellon University, Columbia University, and companies such as Cisco Systems and Bell Labs. RSVP’s architecture aimed to integrate with routing infrastructures built from protocols like Open Shortest Path First, Border Gateway Protocol, and experimental overlays used in academic testbeds such as PlanetLab. Though influential, RSVP saw limited backbone deployment compared with approaches favored by large providers like AT&T, Verizon Communications, and content networks operated by Akamai Technologies.

Protocol Architecture and Operation

RSVP’s architecture separates reservation signalling from packet forwarding, enabling hosts and routers to coordinate resource allocation. End systems—clients and servers implementing APIs from environments including POSIX and Microsoft Windows NT—send RSVP messages that traverse network elements running router software from vendors like Juniper Networks and Cisco Systems. RSVP uses soft state maintained in routers, refreshed periodically by receivers and senders, aligning with design patterns used in projects at Massachusetts Institute of Technology and standards from International Organization for Standardization. The control plane interacts with the forwarding plane managed by hardware platforms from Intel Corporation and Broadcom. RSVP also assumes interaction with admission control modules influenced by concepts developed at Bell Labs and research labs at AT&T Shannon Laboratory.

Message Types and Flow

RSVP defines several message types to establish, refresh, and tear down reservations. Key messages include PATH messages propagated from senders and RESV messages generated by receivers; these mirror signalling approaches in other protocols standardized by the Internet Engineering Task Force working groups. PATH messages carry traffic descriptors similar to specifications found in multimedia frameworks from Apple Inc. and Microsoft Corporation, while RESV messages express reservation requests comparable to quality mechanisms proposed in projects at Stanford University and Princeton University. Additional messages such as PATHERR and RESVERR report errors in signaling comparable to diagnostic practices described by engineering teams at Cisco Systems and IBM. Message flows must handle route changes caused by updates from routing systems like Border Gateway Protocol and Open Shortest Path First, requiring RSVP implementations to interact with protocols used in large-scale infrastructures run by operators including Level 3 Communications and NTT Communications.

Quality of Service and Resource Allocation

RSVP enables reservation of resources to support service classes analogous to controlled-load and guaranteed services defined in the same standards body. The protocol works with queuing and scheduling mechanisms implemented in switching equipment from vendors such as Cisco Systems, Juniper Networks, and Arista Networks, and complements algorithms like weighted fair queuing researched at Bell Labs and MIT Laboratory for Computer Science. Admission control decisions reference link capacities specified by hardware vendors Broadcom and Intel Corporation as well as traffic engineering approaches developed by teams at Google LLC and Facebook, Inc. RSVP’s per-flow semantics create scalability trade-offs examined in academic literature from University of California, Berkeley and University of Southern California and in deployment studies by network operators such as Sprint Corporation.

Implementation and Deployment

Multiple implementations of RSVP appeared in router platforms from Cisco Systems, Juniper Networks, and in open-source network stacks like those contributed by projects at FreeBSD and NetBSD communities. Experimental deployments took place in national research and education networks such as Internet2 and JANET and in testbeds operated by laboratories at Lawrence Berkeley National Laboratory. Commercial adoption was limited as service providers favored simpler DiffServ-based architectures advocated by vendors and consortia including TeleManagement Forum and European Telecommunications Standards Institute. Interoperability efforts involved standards bodies like the IETF and operator forums such as RIPE NCC and APNIC.

Security Considerations

RSVP’s signaling messages introduce potential attack vectors including reservation spoofing, state exhaustion, and denial-of-service scenarios noted by security teams at CERT Coordination Center and researchers at SRI International. Mitigations proposed include authentication and integrity mechanisms leveraging protocols developed by Internet Engineering Task Force groups such as IPsec and access control concepts used in network management from Juniper Networks and Cisco Systems. Operational practices advocated by organizations such as National Institute of Standards and Technology and incident response teams at US-CERT emphasize filtering, rate-limiting, and strict policy controls to prevent misuse of reservation facilities. Security reviews from academic centers like Carnegie Mellon University’s CERT and Stanford University stress the need to combine RSVP controls with robust routing security measures promoted by initiatives such as MANRS.

Category:Network protocols