Multi-Protocol Label Switching - MPLS Essay
Multi-Protocol Label Switching, more commonly referred to as MPLS, was defined in the late 1990sas a traffic engineering mechanism to replace IP over ATM in Internet backbones. In the mid-90s efforts were made to combine IP and ATM technologies, the first one being IP switching developed by Ipsilon, competition came very quickly from other companies, notably Cisco with “Tag Switching”, IBM with “Aggregate Route-based IP Switching” and Cascade with “IP Navigator”. All of these solutions had the same goal, which was to improve the throughput and delay performance of …show more content…
MPLS provides universal transport for network integration using ATM, Frame Relay, Ethernet and Optical at the link layer, it supports IPv4, IPv6, IPX and AppleTalk at the network layer, addressing operational problems such as congestion, convergence speed, network upgrading and fault tolerance. It remains independent of layer 2 and layer 3 protocols and provides a means to map IP addresses to simple fixed-length labels used by different packet switching and packet forwarding technologies.
With MPLS data transmission occurs on label switched paths (LSPs), which are a sequence of labels at each node along the path from source to destination. MPLS assigns these labels to the packets at the ingress point (point of entry) of the network. In ATM the label is added to the VCI/VPI field, in an IP network, a 32 bit header, called a “shim” is inserted between the network layer header and the data link layer header. The devices used in MPLS for packet forwarding are classified as label edge routers (LERs) and label switching routers (LSRs). A Forward Equivalence Class (FEC) is assigned to each packet defining the priority and routing with