|
Label Distribution Protocol
Label Distribution Protocol (LDP) is a protocol in which routers capable of Multiprotocol Label Switching (MPLS) exchange label mapping information. Two routers with an established session are called LDP peers and the exchange of information is bi-directional. LDP is used to build and maintain LSP databases that are used to forward traffic through MPLS networks. LDP can be used to distribute the inner label (VC/VPN/service label) and outer label (path label) in MPLS. For inner label distribution, targeted LDP (tLDP) is used. LDP and tLDP discovery runs on UDP port 646 and the session is built on TCP port 646. During the discovery phase hello packets are sent on UDP port 646 to the 'all routers on this subnet' group multicast address (224.0.0.2). However, tLDP unicasts the hello packets to the targeted neighbor's address. LDP The Label Distribution Protocol (LDP) is a protocol defined by the IETF (RFC 5036) for the purpose of distributing labels in an MPLS environment. LDP relie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protocol (computing)
A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any kind of variation of a physical quantity. The protocol defines the rules, syntax, semantics and synchronization of communication and possible error recovery methods. Protocols may be implemented by hardware, software, or a combination of both. Communicating systems use well-defined formats for exchanging various messages. Each message has an exact meaning intended to elicit a response from a range of possible responses pre-determined for that particular situation. The specified behavior is typically independent of how it is to be implemented. Communication protocols have to be agreed upon by the parties involved. To reach an agreement, a protocol may be developed into a technical standard. A programming language describes the same for computations, so there is a close analogy between protocols and programming languages: ''protocols are t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiprotocol Label Switching
Multiprotocol Label Switching (MPLS) is a routing technique in telecommunications networks that directs data from one node to the next based on labels rather than network addresses. Whereas network addresses identify endpoints the labels identify established paths between endpoints. MPLS can encapsulate packets of various network protocols, hence the ''multiprotocol'' component of the name. MPLS supports a range of access technologies, including T1/ E1, ATM, Frame Relay, and DSL. Role and functioning In an MPLS network, labels are assigned to data packets. Packet-forwarding decisions are made solely on the contents of this label, without the need to examine the packet itself. This allows one to create end-to-end circuits across any type of transport medium, using any protocol. The primary benefit is to eliminate dependence on a particular OSI model data link layer (layer 2) technology, and eliminate the need for multiple layer-2 networks to satisfy different types of traffic. M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Label Switched Path
Multiprotocol Label Switching (MPLS) is a routing technique in telecommunications networks that directs data from one node to the next based on labels rather than network addresses. Whereas network addresses identify endpoints the labels identify established paths between endpoints. MPLS can encapsulate packets of various network protocols, hence the ''multiprotocol'' component of the name. MPLS supports a range of access technologies, including T1/ E1, ATM, Frame Relay, and DSL. Role and functioning In an MPLS network, labels are assigned to data packets. Packet-forwarding decisions are made solely on the contents of this label, without the need to examine the packet itself. This allows one to create end-to-end circuits across any type of transport medium, using any protocol. The primary benefit is to eliminate dependence on a particular OSI model data link layer (layer 2) technology, and eliminate the need for multiple layer-2 networks to satisfy different types of traffic. M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interior Gateway Protocol
An interior gateway protocol (IGP) or Interior routing protocol is a type of routing protocol used for exchanging routing table information between gateways (commonly routers) ''within'' an autonomous system (for example, a system of corporate local area networks). This routing information can then be used to route network-layer protocols like IP. Interior gateway protocols can be divided into two categories: distance-vector routing protocols and link-state routing protocols. Specific examples of IGPs include Open Shortest Path First (OSPF), Routing Information Protocol (RIP), Intermediate System to Intermediate System (IS-IS) and Enhanced Interior Gateway Routing Protocol (EIGRP). By contrast, exterior gateway protocols are used to exchange routing information ''between'' autonomous systems and rely on IGPs to resolve routes within an autonomous system. Examples Examples of distance-vector routing protocols: * Routing Information Protocol (RIP) * Routing Information Pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forwarding Information Base
A forwarding information base (FIB), also known as a forwarding table or MAC table, is most commonly used in network bridging, routing, and similar functions to find the proper output network interface controller to which the input interface should forward a packet. It is a dynamic table that maps MAC addresses to ports. It is the essential mechanism that separates network switches from Ethernet hubs. Content-addressable memory (CAM) is typically used to efficiently implement the FIB, thus it is sometimes called a CAM table. Applications at data link layer At the data link layer, a FIB is most notably used to facilitate Ethernet bridging based on MAC addresses. Other data-link-layer technologies using FIBs include Frame Relay, Asynchronous Transfer Mode (ATM) and multiprotocol label switching (MPLS). Bridging The role of an Ethernet switch is to forward Ethernet frames from one port to another. The presence of a FIB is one attribute that separates a switch from a hub. With ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RSVP-TE
Resource Reservation Protocol - Traffic Engineering is an extension of the Resource Reservation Protocol (RSVP) for traffic engineering. It supports the reservation of resources across an IP network. Applications running on IP end systems can use RSVP to indicate to other nodes the nature (bandwidth, jitter, maximum burst, and so forth) of the packet streams they want to receive. RSVP runs on both IPv4 and IPv6. RSVP-TE generally allows the establishment of MPLS label switched paths (LSPs), taking into consideration network constraint parameters such as available bandwidth and explicit hops. Updated by , , , , , , , , and . History , the IETF MPLS working group deprecated CR-LDP and decided to focus purely on RSVP-TE. Operational overhead of RSVP-TE compared to the more widely deployed label distribution protocol (LDP) will generally be higher. This is a classic trade-off between complexity and optimality in the use of technologies in telecommunications network A telecommunic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constraint-based Routing Label Distribution Protocol
Constraint-based Routing Label Distribution Protocol (CR-LDP) is a control protocol used in some computer networks. As of February 2003, the IETF MPLS working group deprecated CR-LDP and decided to focus purely on RSVP-TE. It is an extension of the Label Distribution Protocol (LDP), one of the protocols in the Multiprotocol Label Switching architecture. CR-LDP contains extensions for LDP to extend its capabilities such as setup paths beyond what is available for the routing protocol. For instance, a Label Switched Path can be set up based on explicit route constraints, quality of service constraints, and other constraints. Constraint-based routing (CR) is a mechanism used to meet traffic engineering requirements. These requirements are met by extending LDP for support of constraint-based routed label switched paths (CR-LSPs). Other uses for CR-LSPs include MPLS-based virtual private network A virtual private network (VPN) extends a private network across a public network and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MPLS Networking
Multiprotocol Label Switching (MPLS) is a routing technique in telecommunications networks that directs data from one node to the next based on labels rather than network addresses. Whereas network addresses identify endpoints the labels identify established paths between endpoints. MPLS can encapsulate packets of various network protocols, hence the ''multiprotocol'' component of the name. MPLS supports a range of access technologies, including T1/ E1, ATM, Frame Relay, and DSL. Role and functioning In an MPLS network, labels are assigned to data packets. Packet-forwarding decisions are made solely on the contents of this label, without the need to examine the packet itself. This allows one to create end-to-end circuits across any type of transport medium, using any protocol. The primary benefit is to eliminate dependence on a particular OSI model data link layer (layer 2) technology, and eliminate the need for multiple layer-2 networks to satisfy different types of traffic. M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
