MPLS directs data from one network node to the next based on short path labels rather than long network mpls fundamentals pdf download, avoiding complex lookups in a routing table. MPLS can encapsulate packets of various network protocols, hence its name “multiprotocol”. E1, ATM, Frame Relay, and DSL. MPLS is a scalable, protocol-independent transport.
In an MPLS network, data packets are assigned labels. 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. Ethernet, and eliminate the need for multiple layer-2 networks to satisfy different types of traffic.
Multiprotocol label switching belongs to the family of packet-switched networks. 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.
A number of different technologies were previously deployed with essentially identical goals, such as Frame Relay and ATM. Frame Relay and ATM use “labels” to move frames or cells throughout a network.
The header of the Frame Relay frame and the ATM cell refers to the virtual circuit that the frame or cell resides on. This is different from the forwarding of IP packets. MPLS technologies have evolved with the strengths and weaknesses of ATM in mind. Many network engineers agree that ATM should be replaced with a protocol that requires less overhead, while providing connection-oriented services for variable-length frames.
MPLS is currently replacing some of these technologies in the marketplace. It is highly possible that MPLS will completely replace these technologies in the future, thus aligning these technologies with current and future technology needs. In particular, MPLS dispenses with the cell-switching and signaling-protocol baggage of ATM. Frame Relay and ATM attractive for deploying large-scale networks.
In 1996 a group from Ipsilon Networks proposed a “flow management protocol”. Their “IP Switching” technology, which was defined only to work over ATM, did not achieve market dominance. Cisco Systems introduced a related proposal, not restricted to ATM transmission, called “Tag Switching”.
It was a Cisco proprietary proposal, and was renamed “Label Switching”. The IETF work involved proposals from other vendors, and development of a consensus protocol that combined features from several vendors’ work. 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 works by prefixing packets with an MPLS header, containing one or more labels. This is called a label stack. A label with the value of 1 represents the router alert label.