In computer networking and telecommunications, Multi Protocol Label Switching (MPLS) is a data-carrying mechanism that belongs to the family of packet-switched networks. MPLS operates at an OSI Model layer that is generally considered to lie between traditional definitions of Layer 2 (Data Link Layer) and Layer 3 (Network Layer), and thus is often referred to as a "Layer 2.5" protocol. It was designed to provide a unified data-carrying service for both circuit-based clients and packet-switching clients which provide a datagram service model. It can be used to carry many different kinds of traffic, including IP packets, as well as native ATM, SONET, and Ethernet frames. 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 2000. ... 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. ... Network congestion avoidance is a process used in computer networks to avoid congestion. ... 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. ... The Internet Protocol (IP) is a data-oriented protocol used for communicating data across a packet-switched internetwork. ... Internet Protocol version 4 (IPv4) is the fourth iteration of the Internet Protocol (IP) and it is the first version of the protocol to be widely deployed. ... Internet Protocol version 6 (IPv6) is a network layer for packet-switched internetworks. ... The Open Shortest Path First (OSPF) protocol is a hierarchical interior gateway protocol (IGP) for routing in Internet Protocol, using a link-state in the individual areas that make up the hierarchy. ... Is Is is Yeah Yeah Yeahs third EP, to be released on July 24, 2007. ... The Border Gateway Protocol (BGP) is the core routing protocol of the Internet. ... IPsec (IP security) is a suite of protocols for securing Internet Protocol (IP) communications by authenticating and/or encrypting each IP packet in a data stream. ... 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. ... The Internet Group Management Protocol (IGMP) is a communications protocol used to manage the membership of Internet Protocol multicast groups. ... The data link layer is layer two of the seven-layer OSI model as well as of the five-layer TCP/IP reference model. ... IEEE 802. ... The IEEE 802. ... Wi-Fi (IPA: ) is the common name for a popular wireless technology used in home networks, mobile phones, video games and more. ... 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. ... ARCNET (also CamelCased as ARCnet, an acronym from Attached Resource Computer NETwork) is a local area network (LAN) protocol, similar in purpose to Ethernet or Token Ring. ... Link Layer Topology Discovery (LLTD) is a licensed data link layer protocol for network topology discovery and quality of service diagnostics, developed by Microsoft as part of their Windows Rally set of technologies. ... This article does not cite any references or sources. ... The Ethernet physical layer is the physical layer component of the Ethernet standard. ... RS-232 (also referred to as EIA RS-232C or V.24) is a standard for serial binary data interchange between a DTE (Data terminal equipment) and a DCE (Data communication equipment). ... Synchronous optical networking, is a method for communicating digital information using lasers or light-emitting diodes (LEDs) over optical fiber. ... 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. ... This article or section is in need of attention from an expert on the subject. ... Telecommunication involves the transmission of signals over a distance for the purpose of communication. ... In computer networking and telecommunications, packet switching is a communications paradigm in which packets (messages or fragments of messages) are individually routed between nodes, with no previously established communication path. ... The Open Systems Interconnection Basic Reference Model (OSI Reference Model or OSI Model for short) is a layered, abstract description for communications and computer network protocol design. ... The data link layer is layer two of the seven-layer OSI model as well as of the five-layer TCP/IP reference model. ... 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. ... A telecommunication circuit is defined as follows: The complete path between two terminals over which one-way or two-way communications may be provided. ... Packet switching is a communications paradigm in which packets (discrete blocks of data) are routed between nodes over data links shared with other traffic. ... A packet is the fundamental unit of information carriage in all modern computer networks. ... In information technology, a packet is a formatted block of data carried by a packet mode computer network. ...

A number of different technologies were previously deployed with essentially identical goals, such as frame relay and ATM. MPLS is now replacing these technologies in the marketplace, mostly because it is better aligned with current and future technology needs.^{[citation needed]} 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. ... 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. ...

In particular, MPLS dispenses with the cell-switching and signaling-protocol baggage of ATM. MPLS recognizes that small ATM cells are not needed in the core of modern networks, since modern optical networks (as of 2001) are so fast (at 10 Gbit/s and well beyond) that even full-length 1500 byte packets do not incur significant real-time queuing delays (the need to reduce such delays — e.g., to support voice traffic — was the motivation for the cell nature of ATM).

At the same time, MPLS attempts to preserve the traffic engineering and out-of-band control that made frame relay and ATM attractive for deploying large-scale networks. Teletraffic engineering is the application of traffic engineering theory to telecommunications. ... Out-of-band signaling is telecommunication signaling (exchange of information in order to control a telephone call) that is done on a channel that is dedicated for the purpose and separate from the channels used for the telephone call. ...

MPLS was originally proposed by a group of engineers from Ipsilon Networks, but their "IP Switching" technology, which was defined only to work over ATM, did not achieve market dominance. Cisco Systems, Inc. introduced a related proposal, not restricted to ATM transmission, called "Tag Switching" when it was a Cisco proprietary proposal, and was renamed "Label Switching" when it was handed over to the IETF for open standardization. The IETF work involved proposals from other vendors, and development of a consensus protocol that combined features from several vendors' work. Ipsilon Networks was a computer networking company which specialised in IP switching. ... Cisco Systems, Inc. ... 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. ...

One original motivation was to allow the creation of simple high-speed switches, since for a significant length of time it was impossible to forward IP packets entirely in hardware. However, advances in VLSI have made such devices possible. Therefore the advantages of MPLS primarily revolve around the ability to support multiple service models and perform traffic management. MPLS also offers a robust recovery framework^[1] that goes beyond the simple protection rings of synchronous optical networking (SONET/SDH). It has been suggested that VHSIC be merged into this article or section. ... Synchronous optical networking, is a method for communicating digital information using lasers or light-emitting diodes (LEDs) over optical fiber. ...

While the traffic management benefits of migrating to MPLS are quite valuable (better reliability, increased performance), there is a significant loss of visibility and access into the MPLS cloud for IT departments.^[2]

How MPLS works

MPLS works by prefixing packets with an MPLS header, containing one or more 'labels'. This is called a label stack. Simple representation of a stack In computer science, a stack is a temporary abstract data type and data structure based on the principle of Last In First Out (LIFO). ...

Each label stack entry contains four fields:

• A 20-bit label value..
• a 3-bit field for QoS (Quality of Service) priority (experimental).
• a 1-bit bottom of stack flag. If this is set, it signifies that the current label is the last in the stack.
• an 8-bit TTL (time to live) field.

These MPLS-labeled packets are switched after a Label Lookup/Switch instead of a lookup into the IP table. As mentioned above, when MPLS was conceived, Label Lookup and Label Switching were faster than a RIB lookup because they could take place directly within the switched fabric and not the CPU. In the fields of packet-switched networks and computer networking, the traffic engineering term Quality of Service, abbreviated QoS, refers to resource reservation control mechanisms. ... Time to live (sometimes abbreviated TTL) is a limit on the period of time or number of iterations or transmissions in computer and computer network technology that a unit of data (e. ... Label switching is a form of network relaying to overcome the problems perceived by traditional IP-table switching. ... In computer networking a routing table is an electronic table (file) or database type object that is stored in a router or a networked computer. ... Switched Fabric is a Fibre Channel topology where many devices connect with each other via Fibre Channel switches. ... CPU can stand for: in computing: Central processing unit in journalism: Commonwealth Press Union in law enforcement: Crime prevention unit in software: Critical patch update, a type of software patch distributed by Oracle Corporation in Macleans College is often known as Ash Lim. ...

The entry and exit points of an MPLS network are called Label Edge Routers (LER), which, respectively, push an MPLS label onto the incoming packet and pop it off the outgoing packet. Routers that perform routing based only on the label are called Label Switch Routers (LSR). In some applications, the packet presented to the LER already may have a label, so that the new LSR pushes a second label onto the packet. For more information see Penultimate Hop Popping. Edge router: A router that connects clients to the internet A Label Edge Router (LER) is a router that operates at the edge of an MPLS network. ... A Label Switch Router (LSR) is a type of a router located in the middle of a Multiprotocol Label Switching (MPLS) network. ... Penultimate Hop Popping (PHP) is a function performed by certain routers in an MPLS enabled network. ...

Labels are distributed between LERs and LSRs using the “Label Distribution Protocol” (LDP)^[3]. Label Switch Routers in an MPLS network regularly exchange label and reachability information with each other using standardized procedures in order to build a complete picture of the network they can then use to forward packets. Label Switch Paths (LSPs) are established by the network operator for a variety of purposes, such as to create network-based IP Virtual Private Networks or to route traffic along specified paths through the network. In many respects, LSPs are no different than PVCs in ATM or Frame Relay networks, except that they are not dependent on a particular Layer 2 technology.^[4] Label Distribution Protocol (LDP) is a protocol using which two label-switched routers (LSR) exchange label mapping information. ...

In the specific context of an MPLS-based Virtual Private Network (VPN), LSRs that function as ingress and/or egress routers to the VPN are often called PE (Provider Edge) routers. Devices that function only as transit routers are similarly called P (Provider) routers. See RFC 2547. The job of a P router is significantly easier than that of a PE router, so they can be less complex and may be more dependable because of this. VPN redirects here. ... An ingress router is a Label Switch Router that is a starting point (source) for a given LSP. An ingress router may be an egress router or an intermediate router for any other LSP(s). ...

When an unlabeled packet enters the ingress router and needs to be passed on to an MPLS tunnel, the router first determines the forwarding equivalence class (FEC) the packet should be in, and then inserts one or more labels in the packet's newly-created MPLS header. The packet is then passed on to the next hop router for this tunnel. A FEC (Forward Equivalence Class) is a set of packets that can be handled ( Forwarded) in the same manner and thus is suitable for binding to a single MPLS label. ...

When a labeled packet is received by an MPLS router, the topmost label is examined. Based on the contents of the label a swap, push (impose) or pop (dispose) operation can be performed on the packet's label stack. Routers can have prebuilt lookup tables that tell them which kind of operation to do based on the topmost label of the incoming packet so they can process the packet very quickly.

In a swap operation the label is swapped with a new label, and the packet is forwarded along the path associated with the new label.

In a push operation a new label is pushed on top of the existing label, effectively "encapsulating" the packet in another layer of MPLS. This allows hierarchical routing of MPLS packets. Notably, this is used by MPLS VPNs. MPLS-VPN is a family of methods for harnessing the power of Multiprotocol Label Switching (MPLS) to create virtual private networks (VPNs). ...

In a pop operation the label is removed from the packet, which may reveal an inner label below. This process is called "decapsulation". If the popped label was the last on the label stack, the packet "leaves" the MPLS tunnel. This is usually done by the egress router, but see PHP below.

During these operations, the contents of the packet below the MPLS Label stack are not examined. Indeed transit routers typically need only to examine the topmost label on the stack. The forwarding of the packet is done based on the contents of the labels, which allows "protocol-independent packet forwarding" that does not need to look at a protocol-dependent routing table and avoids the expensive IP longest prefix match at each hop. Simple representation of a stack In computer science, a stack is a temporary abstract data type and data structure based on the principle of Last In First Out (LIFO). ... In computer networking a routing table is an electronic table (file) or database type object that is stored in a router or a networked computer. ... Longest prefix match refers to an algorithm used by routers in Internet Protocol (IP) networking to select an entry from a routing table. ...

At the egress router, when the last label has been popped, only the payload remains. This can be an IP packet, or any of a number of other kinds of payload packet. The egress router must therefore have routing information for the packet's payload, since it must forward it without the help of label lookup tables. An MPLS transit router has no such requirement.

In some special cases, the last label can also be popped off at the penultimate hop (the hop before the egress router). This is called Penultimate Hop Popping (PHP). This may be interesting in cases where the egress router has lots of packets leaving MPLS tunnels, and thus spends inordinate amounts of CPU time on this. By using PHP, transit routers connected directly to this egress router effectively offload it, by popping the last label themselves. Penultimate Hop Popping (PHP) is a function performed by certain routers in an MPLS enabled network. ...

MPLS can make use of existing ATM network infrastructure, as its labeled flows can be mapped to ATM virtual circuit identifiers, and vice versa.

Installing and removing MPLS paths

There are two standardized protocols for managing MPLS paths: CR-LDP (Constraint-based Routing Label Distribution Protocol) and RSVP-TE, an extension of the RSVP protocol for traffic engineering. As of February 2003, as documented in RFC 3468^[5], the IETF MPLS working group deprecated LDP and decided to focus purely on RSVP-TE ^[6], defined in RFC 3209. The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ... Resource Reservation Protocol Protocol that supports the reservation of resources across an IP network. ... 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. ...

Extensions of the BGP protocol, starting with RFC 2547, can be used to manage an MPLS path, including RFC 3107 and RFC 4781. ^{[7] [8]}. The border gateway protocol (BGP) is one of the core routing protocols in the Internet. ...

An MPLS header does not identify the type of data carried inside the MPLS path. If one wants to carry two different types of traffic between the same two routers, with different treatment from the core routers for each type, one has to establish a separate MPLS path for each type of traffic.

Comparison of MPLS versus IP

MPLS cannot be compared to IP as a separate entity because it works in conjunction with IP and IP's IGP routing protocols. MPLS gives IP networks simple traffic engineering, the ability to transport Layer 3 (IP) VPNs with overlapping address spaces, and support for Layer 2 pseudowires (with Any Transport Over MPLS, or ATOM - see Martini draft). Routers with programmable CPUs and without TCAM/CAM or another method for fast lookups may also see a limited increase in the performance. A set of routing protocols that are used within an autonomous system are referred to as interior gateway protocols (IGP). ... In computer networking and telecommunications, a Pseudowire (PW) is an emulation of a native service over a Packet Switched Network (PSN). ... The Martini drafts are contributions made to the IETFs PWE3 (Pseudo Wire Emulation Edge-to-Edge) working group by Luca Martini of Level 3 Communications and a number of other authors. ... Content-addressable memory (CAM) is a special type of computer memory used in certain very high speed searching applications. ...

MPLS relies on IGP routing protocols to construct its label forwarding table, and the scope of any IGP is usually restricted to a single carrier for stability and policy reasons. As there is still no standard for carrier-carrier MPLS it is not possible to have the same MPLS service (Layer2 or Layer3 VPN) covering more than one operator. A Virtual Private Network, or VPN, is a private communications network usually used within a company, or by several different companies or organizations, communicating over a public network. ...

MPLS Traffic Engineering

MPLS Traffic Engineering provides benefits over a pure-IP network by allowing greater control over the spread of traffic in the network. The path of an LSP can either be (a) explicitly configured hop by hop, (b) dynamically routed by the Constrained Shortest Path First CSPF algorithm, or (c) configured as a loose route that avoids a particular IP or that is partly explicit and partly dynamic. In a pure IP network, the shortest path to a destination is chosen even when it becomes more congested. Meanwhile, in an IP network with MPLS Traffic Engineering CSPF routing, constraints such as the RSVP bandwidth of the traversed links can also be considered, such that the shortest path with available bandwidth will be chosen. MPLS Traffic Engineering relies upon the use of TE extensions to OSPF or IS-IS and RSVP. Besides the constraint of RSVP bandwidth, users can also define their own constraints by specifying link attributes and special requirements for tunnels to route (or to not route) over links with certain attributes. ^[9] Constrained Shortest Path First (CSPF) is an extension of shortest path algorithms like OSPF and IS-IS. The path computed using CSPF is a shortest path fulfilling set of constrains. ...

MPLS local protection (Fast Reroute)

Main article: MPLS local protection

In the event of a network element failure when recovery mechanisms are employed at the IP layer, restoration may take several seconds which is unacceptable for real-time applications (such as VoIP)^{[10] [11][12]}. In contrast, MPLS local protection meets the requirements of real-time applications with recovery times comparable to those of SONET rings (up to 50ms).^[10][12][13] In MPLS local protection (also called MPLS local restoration or MPLS Fast Reroute) is a local restoration network resiliency mechanism. ... IP Telephony, also called Internet telephony, is the technology that makes it possible to have a telephone conversation over the Internet or a dedicated Internet Protocol (IP) network instead of dedicated voice transmission lines. ... In MPLS local protection (also called MPLS local restoration or MPLS Fast Reroute) is a local restoration network resiliency mechanism. ... Synchronous Optical Networking, commonly known as SONET, is a standard for communicating digital information over optical fiber. ...

Comparison of MPLS versus Frame Relay

Frame relay aimed to make more efficient use of existing physical resources, which allow for the underprovisioning of data services by telecommunications companies (telcos) to their customers, as clients were unlikely to be utilizing a data service 100 percent of the time. In more recent years, frame relay has acquired a bad reputation in some markets because of excessive bandwidth overbooking by these telcos. It has been suggested that this article or section be merged with Overselling. ...

Telcos often sell frame relay to businesses looking for a cheaper alternative to dedicated lines; its use in different geographic areas depended greatly on governmental and telecommunication companies' policies. Some of the early companies to make frame relay products included StrataCom (later acquired by Cisco Systems) and Cascade Communications (later acquired by Ascend Communications and then by Lucent Technologies). In computer networks and telecommunications, a dedicated line is a communications cable dedicated to a specific application, in contrast with a shared resource such as the telephone network or the Internet. ... StrataCom, Inc. ... Cisco redirects here. ... Cascade Communications was a Westford, Massachusetts based manufacturer of communications equipment. ... Ascend Communications was an Alameda, California based manufacturer of communications equipment that was later purchased by Lucent Technologies in 1999. ... On September 30, 1996, AT&T spun off its Systems and Technology units (AT&T Technologies, Inc. ...

AT&T is currently (as of June 2007) the largest frame relay service provider in the United States, with local networks in 22 states, plus national and international networks. This number is expected to change between 2007 and 2009 when most of these frame relay contracts expire. Many customers are likely to migrate from frame relay to MPLS over IP or Ethernet within the next two years, which in many cases will reduce costs and improve manageability and performance of their wide area networks.^{[14] [15]} This article is about the current AT&T. For the 1885-2005 company, see American Telephone & Telegraph. ...

Comparison of MPLS versus ATM

While the underlying protocols and technologies are different, both MPLS and ATM provide a connection-oriented service for transporting data across computer networks. In both technologies, connections are signaled between endpoints, connection state is maintained at each node in the path, and encapsulation techniques are used to carry data across the connection. Excluding differences in the signaling protocols (RSVP/LDP for MPLS and PNNI for ATM) there still remain significant differences in the behavior of the technologies. 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. ... A connection-oriented networking protocol is one which identifies traffic flows by some connection identifier rather than by explicitly listing source and destination addresses. ...

The most significant difference is in the transport and encapsulation methods. MPLS is able to work with variable length packets while ATM transports fixed-length (53 byte) cells. Packets must be segmented, transported and re-assembled over an ATM network using an adaption layer, which adds significant complexity and overhead to the data stream. MPLS, on the other hand, simply adds a label to the head of each packet and transmits it on the network.

Differences exist, as well, in the nature of the connections. An MPLS connection (LSP) is uni-directional - allowing data to flow in only one direction between two endpoints. Establishing two-way communications between endpoints requires a pair of LSPs to be established. Because 2 LSPs are required for connectivity, data flowing in the forward direction may use a different path from data flowing in the reverse direction. ATM point-to-point connections (Virtual Circuits), on the other hand, are bi-directional, allowing data to flow in both directions over the same path (bi-directional are only svc ATM connections; pvc ATM connections are uni-directional). 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). ... Two-way communication is a form of transmission in which both parties involved transmit information. ...

Both ATM and MPLS support tunnelling of connections inside connections. MPLS uses label stacking to accomplish this while ATM uses Virtual Paths. MPLS can stack multiple labels to form tunnels within tunnels. The ATM Virtual Path Indicator (VPI) and Virtual Circuit Indicator (VCI) are both carried together in the cell header, limiting ATM to a single level of tunnelling.

The biggest single advantage that MPLS has over ATM is that it was designed from the start to be complementary to IP. Modern routers are able to support both MPLS and IP natively across a common interface allowing network operators great flexibility in network design and operation. ATM's incompatibilities with IP require complex adaptation making it largely unsuitable in today's predominantly IP networks.

MPLS deployment

MPLS is currently in use in large "IP Only" networks, and is standardized by IETF in RFC 3031. The Internet Engineering Task Force (IETF) is charged with developing and promoting Internet standards. ...

In practice, MPLS is mainly used to forward IP datagrams and Ethernet traffic. Major applications of MPLS are Telecommunications traffic engineering and MPLS VPN. The Internet Protocol (IP) is a data-oriented protocol used for communicating data across a packet-switched internetwork. ... Ethernet is a large, diverse family of frame-based computer networking technologies that operate at many speeds for local area networks (LANs). ... Teletraffic engineering is the application of traffic engineering theory to telecommunications. ... MPLS-VPN is a family of methods for harnessing the power of Multiprotocol Label Switching (MPLS) to create virtual private networks (VPNs). ...

Competitors to MPLS

MPLS can exist in both IPv4 environment (IPv4 routing protocols) and IPv6 environment (IPv6 routing protocols). The major goal of MPLS development - the increase of routing speed - is no longer relevant because of the usage of ASIC, TCAM and CAM-based switching. Therefore the major usage of MPLS is to implement limited traffic engineering and Layer 3/Layer 2 “service provider type” VPNs over existing IPv4 networks. The only competitors to MPLS are technologies like L2TPv3 that also provide services such as service provider Layer 2 and Layer 3 VPNs. Internet Protocol version 4 (IPv4) is the fourth iteration of the Internet Protocol (IP) and it is the first version of the protocol to be widely deployed. ... Internet Protocol version 6 (IPv6) is a network layer for packet-switched internetworks. ... This article does not cite any references or sources. ... Content-addressable memory (CAM) is a special type of computer memory used in certain very high speed searching applications. ... Layer 2 Tunneling Protocol Version 3 is a draft version of L2TP that is proposed as an alternative protocol to MPLS for encapsulation of multiprotocol Layer 2 communications traffic over IP networks. ...

IEEE 1355 is a completely unrelated technology that does something similar in hardware. IEEE-1355, IEC 14575, or ISC 14575 is a data communications standard, the IEEE Standard for Heterogeneous Interconnect (HIC). ...

IPv6 references: Grossetete, Patrick, IPv6 over MPLS, Cisco Systems 2001; Juniper Networks IPv6 and Infranets White Paper; Juniper Networks DoD's Research and Engineering Community White Paper.

Access to MPLS networks

MPLS supports a range of access technologies, including T1, ATM and frame relay. While less expensive DSL connections may also be used, they don’t allow network users to reap the significant MPLS benefit of class of service application prioritization. In January 2008, however, New Edge Networks announced plans to make traffic prioritization on its MPLS network available via DSL access. For the guitar distortion pedal, see BOSS DS-1. ... 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. ... 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. ... DSL may refer to: Damn Small Linux Dark and Shattered Lands, a MUD based loosely on Forgotten Realms and Dragonlance books. ... Class of Service (CoS) is a 3 bit field within a layer two Ethernet frame header when using IEEE 802. ...

Benefits of MPLS

MPLS provides networks with a more efficient way to manage applications and move information between locations. With the convergence of voice, video and data applications, business networks face increasing traffic demands. MPLS enables class of service (CoS) tagging and prioritization of network traffic, so administrators may specify which applications should move across the network ahead of others. This function makes an MPLS network especially important to firms that need to ensure the performance of low-latency applications such as VoIP and their other business-critical functions. MPLS carriers differ on the number of classes of service they offer and in how these CoS tiers are priced. ^[16] Class of Service (CoS) is a 3 bit field within a layer two Ethernet frame header when using IEEE 802. ...

See also

• VPLS, virtual LANs over MPLS

Virtual private LAN service (VPLS) is a way to provide Ethernet based Multipoint to Multipoint communication over IP only networks. ...

Major Vendors of MPLS equipment

• Alcatel-Lucent
• Nokia Siemens Networks
• Foundry Networks
• Juniper Networks
• Adtran
• Cisco Systems
• Ericsson (Redback)
• Tellabs
• Nortel
• MRV Communications
• Mikrotik
• Huawei
• ECI Telecom
• General DataComm

Alcatel Lucent (or Alcatel-Lucent according to some sources) is the name of the new company formed after the merge agreement signed by Alcatel and Lucent Technologies. ... Nokia Siemens Networks (NSN) is a telecommunications solutions supplier which was created as the result of a merger (by means of a 50-50 joint venture) between Siemens AGs COM division (minus its Enterprise business unit) and Nokias Network Business Group. ... Foundry Networks is a network system vendor selling high-end managed ethernet switches. ... Juniper Networks NASDAQ: JNPR is a telecommunications equipment company. ... Adtran is a telecommunications equipment manufacturer based in Huntsville, Alabama, U.S.A. It was founded in 1986 by Mark C. Smith and Lonnie McMillian. ... Cisco redirects here. ... For other uses, see Ericsson (disambiguation). ... Tellabs, Inc. ... Northern Telecommunications Networks, commonly known as Nortel, is a telecommunications equipment manufacturer headquartered in Canada. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Mikrotikls, also known as Mikrotik, is a Latvian networking equipment manufacturer. ... Huawei Technologies Co. ... ECI Telecom Ltd NASDAQ: ECIL, is a telecommunication equipment manufacturer based in Petah Tikva, Israel. ...

References

Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... is the 33rd day of the year in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 300th day of the year (301st in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 300th day of the year (301st in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 300th day of the year (301st in leap years) in the Gregorian calendar. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Anno Domini (or common era), in accordance with the Gregorian calendar. ... is the 15th day of the year in the Gregorian calendar. ...

Books

• "Deploying IP and MPLS QoS for Multiservice Networks: Theory and Practice" by John Evans, Clarence Filsfils (Morgan Kaufmann, 2007, ISBN 0-12-370549-5)
• Rick Gallaher's MPLS Training Guide (ISBN: 1932266003)

External links

• Introduction to MPLS.
• Home of MPLS standards.
• MPLS Resource Center: industry news and MPLS operators mailing list
• A page containing simple and starter mpls tutorial.
• Using MPLS for VPNs
• MPLS Lecture Notes
• MPLS - Directory & Informational Resource
• New Edge's MPLS page
• OpenSimMPLS. MPLS network simulator. Open source and free of cost.
• Negotiating an MPLS Contract.
• Data Communication Lectures of Manfred Lindner - Part MPLS