The Resource ReSerVation Protocol (RSVP), described in RFC 2205, is a Transport layer protocol designed to reserve resources across a network for an integrated services Internet. "RSVP does not transport application data but is rather an Internet control protocol, like ICMP, IGMP, or routing protocols" - RFC 2205. RSVP provides receiver-initiated setup of resource reservations for multicast or unicast data flows with scaling and robustness. In computing and telecommunications, the transport layer is the second highest layer in the four and five layer TCP/IP reference models, where it responds to service requests from the application layer and issues service requests to the Internet layer. ... The Transmission Control Protocol (TCP) is one of the core protocols of the Internet protocol suite. ... User Datagram Protocol (UDP) is one of the core protocols of the Internet protocol suite. ... The Datagram Congestion Control Protocol (DCCP) is a message-oriented transport layer protocol that is currently under development in the IETF. Applications that might make use of DCCP include those with timingconstraints on the delivery of data such that reliable in-order delivery, when combined with congestion control, is likely... In the field of computer networking, the IETF Signaling Transport (SIGTRAN) working group defined the Stream Control Transmission Protocol (SCTP) as a transport layer protocol in 2002. ... The Real-time Transport Protocol (or RTP) defines a standardized packet format for delivering audio and video over the Internet. ... The Internet Group Management Protocol (IGMP) is a communications protocol used to manage the membership of Internet Protocol multicast groups. ... The network layer is third layer out of seven in OSI model and it is the third layer out of five in TCP/IP model. ... 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In computer networking, the Address Resolution Protocol (ARP) is the standard method for finding a hosts hardware address when only its network layer address is known. ... Reverse Address Resolution Protocol (RARP) is a network layer protocol used to obtain an IP address for a given hardware address (such as an Ethernet address). ... This article is chiefly about the Routing Information Protocol (RIP) for the Internet Protocol, but also discusses some other routing information protocols. ... The Internet Control Message Protocol (ICMP) is one of the core protocols of the Internet protocol suite. ... The ICMP for IPv6 (Internet Control Message Protocol Version 6) is an integral part of the IPv6 architecture and must be completely supported by all IPv6 implementations. ... This article does not cite any references or sources. ... IEEE 802. ... The IEEE 802. ... Official Wi-Fi logo Wi-Fi (pronounced wye-fye, IPA: ), also unofficially known as Wireless Fidelity, is a wireless technology brand owned by the Wi-Fi Alliance intended to improve the interoperability of wireless local area network products based on the IEEE 802. ... Official WiMax logo WiMAX, the Worldwide Interoperability for Microwave Access, is a telecommunications technology aimed at providing wireless data over long distances in a variety of ways, from point-to-point links to full mobile cellular type access. ... Asynchronous Transfer Mode (ATM) is a cell relay, packet switching network and data link layer protocol which encodes data traffic into small (53 bytes; 48 bytes of data and 5 bytes of header information) fixed-sized cells. ... Dynamic synchronous Transfer Mode , or DTM for short, is a network protocol. ... Token-Ring local area network (LAN) technology was developed and promoted by IBM in the early 1980s and standardised as IEEE 802. ... Ethernet is a large, diverse family of frame-based computer networking technologies that operate at many speeds for local area networks (LANs). ... In computer networking, fiber-distributed data interface (FDDI) is a standard for data transmission in a local area network that can extend in range up to 200 km (124 miles). ... In the context of computer networking, frame relay consists of an efficient data transmission technique used to send digital information quickly and cheaply in a relay of frames to one or many destinations from one or many end-points. ... General Packet Radio Service (GPRS) is a Mobile Data Service available to users of Global System for Mobile Communications (GSM) and IS-136 mobile phones. ... Evolution-Data Optimized or Evolution-Data only, abbreviated as EV-DO or EVDO and often EV, is one telecommunications standard for the wireless transmission of data through radio signals, typically for broadband Internet access. ... High-Speed Packet Access (HSPA) is a collection of mobile telephony protocols that extend and improve the performance of existing UMTS protocols. ... High-Level Data Link Control (HDLC) is a bit-oriented synchronous data link layer protocol developed by the International Organization for Standardization (ISO). ... In computing, the Point-to-Point Protocol, or PPP, is commonly used to establish a direct connection between two nodes. ... The Point-to-Point Tunneling Protocol (PPTP) is a method for implementing virtual private networks. ... In computer networking, the Layer 2 Tunneling Protocol (L2TP) is a tunneling protocol used to support virtual private networks (VPNs). ... ISDN redirects here. ... This article does not cite any references or sources. ... IEEE photograph of a diagram with the original terms for describing Ethernet drawn by Robert M. Metcalfe around 1976. ... For other uses, see Modem (disambiguation). ... For other uses, see Power band. ... It has been suggested that this article be split into articles entitled Synchronous optical networking, SONET and Synchronous digital hierarchy. ... There are very few or no other articles that link to this one. ... Optical fibers An optical fiber (or fibre) is a glass or plastic fiber designed to guide light along its length. ... Coaxial Cable For the weapon, see coaxial weapon. ... 25 Pair Color Code Chart 10BASE-T UTP Cable Twisted pair cabling is a common form of wiring in which two conductors are wound around each other for the purposes of cancelling out electromagnetic interference known as crosstalk. ... In computing and telecommunications, the transport layer is the second highest layer in the four and five layer TCP/IP reference models, where it responds to service requests from the application layer and issues service requests to the Internet layer. ... This article concerns communication between pairs of electronic devices. ... This article or section is in need of attention from an expert on the subject. ... In computer networking, IntServ or integrated services is an architecture, which specifies the elements to guarantee quality of service (QoS) on networks. ... IP Multicast is a method of forwarding IP datagrams to a group of interested receivers. ... In computer networks, unicast is the sending of information packets to a single destination. ...

RSVP can be used by either hosts or routers to request or deliver specific levels of quality of service (QoS) for application data streams or flows. RSVP defines how applications place reservations and how they can relinquish the reserved resources once the need for them has ended. RSVP operation will generally result in resources being reserved in each node along a path. This article is about a computer networking device. ... In the fields of packet-switched networks and computer networking, the traffic engineering term Quality of Service (QoS) refers to control mechanisms that can provide different priority to different users or data flows, or guarantee a certain level of performance to a data flow in accordance with requests from the...

RSVP is not itself a routing protocol and was designed to interoperate with current and future routing protocols. The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ...

RSVP by itself is rarely deployed in telecommunications networks today ^{[citation needed]} but the traffic engineering extension of RSVP, or RSVP-TE, is becoming more widely accepted nowadays in many QoS-oriented networks. Teletraffic engineering is the application of traffic engineering theory to telecommunications. ... Resource Reservation Protocol Protocol that supports the reservation of resources across an IP network. ...

Main attributes

1. RSVP requests resources for simplex flows: a traffic stream in only one direction from sender to one or more receivers.
2. RSVP is not a routing protocol but works with current and future routing protocols.
3. RSVP is receiver oriented: in that the receiver of a data flow initiates and maintains the resource reservation for that flow.
4. RSVP maintains soft state (the reservation at each node needs a periodic refresh) of the host and routers' resource reservations, hence supporting dynamic automatic adaptation to network changes.
5. RSVP provides several reservation styles (a set of reservation options) and allows for future styles to be added to protocol revisions to fit varied applications.
6. RSVP transports and maintains traffic and policy control parameters that are opaque to RSVP.

A simplex communication system is one where all signals flow in one direction. ...

History and related standards

RSVP is described in a series of RFC documents from the IETF:

RFC 2205

The version 1 functional specification was described in RFC 2205 (Sept. 1997) by IETF. Version 1 describes the interface to admission (traffic) control that is based "only" on resource availability. Later RFC2750 extended the admission control support. The Internet Engineering Task Force (IETF) develops and promotes Internet standards, cooperating closely with the W3C and ISO/IEC standard bodies; and dealing in particular with standards of the TCP/IP and Internet protocol suite. ...

RFC 2210

RFC 2210 defines the use of RSVP with controlled-load RFC 2211 and guaranteed RFC 2212 QoS control services. More details in Integrated Services. Also defines the usage and data format of the data objects (that carry resource reservation information) defined by RSVP in RFC 2205. In computer networking, IntServ or integrated services is an architecture, which specifies the elements to guarantee quality of service (QoS) on networks. ...

RFC 2211

RFC 2211 specifies the network element behavior required to deliver Controlled-Load services.

RFC 2212

RFC 2212 specifies the network element behavior required to deliver guaranteed QoS services.

RFC 2750

RFC 2750 describes a proposed extension for supporting generic policy based admission control in RSVP. The extension included a specification of policy objects and a description on handling policy events. (January 2000). Look up policy in Wiktionary, the free dictionary. ...

RFC 3936

RFC 3936 describes current best practices, and specifies procedures for modifying the Resource reSerVation Protocol (October 2004).

RFC 4495

(May 2006)

Key concepts

The two key concepts of RSVP reservation model are flowspec and filterspec:

Flowspec

RSVP reserves resources for a flow. A flow is identified by the destination address, the protocol identifier and optionally the destination port. In MPLS a flow is defined as a LSP. For each flow RSVP also identifies the particular quality of service required by the flow although it does not understand the specific information of the flow QoS. This QoS specific information is called a flowspec and RSVP passes the flowspec from the application to the hosts and routers along the path. Those systems then analyse the flowspec to accept and reserve the resources. A flowspec consists of: In computer networking and telecommunications, Multi Protocol Label Switching (MPLS) is a data-carrying mechanism that belongs to the family of packet-switched networks. ... In MPLS networking, a Label Switched Path (LSP) is a path through an MPLS network, set up by a signaling protocol such as LDP, RSVP-TE, or CR-LDP. The path is set up based on criteria in the forwarding equivalence class (FEC). ...

1. Service class
2. Reservation spec - defines the QoS
3. Traffic spec - describes the data flow

Filterspec

The filterspec defines the set of packets that shall be affected by a flowspec (i.e. the data packets to receive the QoS defined by the flowspec). A filterspec typically selects a subset of all the packets processed by a node. The selection can depend on any attribute of a packet (e.g. the sender IP address and port).

The currently defined RSVP reservation styles are:

1. Fixed filter - reserves resources for a specific flow.
2. Shared explicit - reserves resources for several flows and all share the resources
3. Wildcard filter - reserves resources for a general type of flow without specifying the flow; all flows share the resources

A RSVP reservation request consists of a flowspec and a filterspec and the pair is called a flowdescriptor. The effects at the node of each spec are that while the flowspec sets the parameters of the packet scheduler at a node, the filterspec sets the parameters at the packet classifier.

Messages

There are two primary types of messages:

• Path messages (path)

The path message is sent from the sender host along the data path and stores the path state in each node along the path.

The path state includes the IP address of the previous node, and some data objects:

1. sender template to describe the format of the sender data
2. sender tspec to describe the traffic characteristics of the data flow
3. adspec that carries advertising data (see RFC 2210 for more details).

• Reservation messages (resv)

The resv message is sent from the receiver to the sender host along the reverse data path. At each node the IP destination address of the resv message will change to the address of the next node on the reverse path and the IP source address to the address of the previous node address on the reverse path.

The resv message includes the flowspec data object that identifies the resources that the flow needs.

The data objects on RSVP messages can be transmitted in any order. For the complete list of RSVP messages and date objects see RFC 2205.

Operation

A RSVP host that needs to send a data flow with specific QoS will transmit a RSVP path message that will travel along the unicast or multicast routes pre-established by the working routing protocol. If the path message arrives at a router that does not understand RSVP, that router forwards the message without interpreting the contents of the message and will not reserve resources for the flow.

When the destination router receives the path message it will:

1. Make a reservation based on the request parameters. For this the admission control and policy control process the request parameters and can either instruct the packet classifier to correctly handle the selected subset of data packets or negotiate with the upper layer how the packet handling should be performed.
2. Forward the request upstream (in the direction of the sender). At each node the resv message flowspec can be modified by a forwarding node (e.g. in the case of a multicast flow reservation the reservations requests can be merged).

Each node in the path can either accept or reject the request. Admission control is a network Quality of Service (QoS) procedure[1]. Admission control determines how bandwidth and latency are allocated to streams with various requirements[2]. Admission control schemes therefore need to be implemented between network edges and core to control the traffic entering the network. ...

Other features

• Encryption - RSVP messages are appended with a message digest created by combining the message contents and a shared key using a message digest algorithm (commonly MD5). The key can be distributed and confirmed using 2 message types: integrity challenge request and integrity challenge response.
• Error reporting - when a node detects an error, an error message is generated with an error code and is propagated upstream on the reverse path to the sender.
• Information on RSVP flow - two types of diagnostic messages allow a network operator to request the RSVP state information on a specific flow.
• Diagnostic facility - An extension to the standard which allows a user to collect information about the RSVP state along a path. RFC2745 - RSVP Diagnostic Messages

In cryptography, MD5 (Message-Digest algorithm 5) is a widely used cryptographic hash function with a 128-bit hash value. ...

References

• "Deploying IP and MPLS QoS for Multiservice Networks: Theory and Practice" by John Evans, Clarence Filsfils (Morgan Kaufmann, 2007, ISBN 0-12-370549-5)

External links

• RSVP Project
• Resource Reservation Protocol

RFCs

• RFC 2205
• RFC 2210
• RFC 2211
• RFC 2212