IP-based Internet prevailed in the mid 90s. The technology is simple and costs little to deploy. However, nowadays IP technology, which relies on the longest match algorithm, is not the most efficient choice for forwarding packets.
In comparison, Asynchronous Transfer Mode (ATM) is much more efficient at forwarding packets. However, ATM technology is a complex protocol with a high deployment cost, which has hindered its widespread popularity and growth.
Users wanted a technology that combines the best that both IP and ATM have to offer. The MPLS technology emerges.
Multiprotocol Label Switching (MPLS) is designed to increase forwarding rates. Unlike IP technology, MPLS analyzes packet headers on the edge of a network, not at each hop. Therefore, packet processing time is shortened.
MPLS supports multi-layer labels, and its forwarding plane is connection-oriented. MPLS is widely used in virtual private network (VPN), traffic engineering (TE), and quality of service (QoS) scenarios.
MPLS takes place between the data link layer and network layer in the TCP/IP protocol stack. MPLS supports label switching between multiple network protocols, as implied by its name. MPLS can use any Layer 2 media to transfer packets, but is not exclusive by any specific protocol on the data link layer.
MPLS is derived from the Internet Protocol version 4 (IPv4). The core MPLS technology can be extended to multiple network protocols, such as the Internet Protocol version 6 (IPv6), Internet Packet Exchange (IPX), Appletalk, DECnet, and Connectionless Network Protocol (CLNP). Multiprotocol in MPLS means that the protocol supports multiple network protocols.
The MPLS technology supports multiple protocols and services and improves data transmission security.