Hi there, Community friends! This time, I will share with you about MPLS. Hope you like it!
The IP-based Internet prevailed in the middle 1990s. However, IP technology is inefficient at forwarding packets because software must search for routes through the longest match algorithm. As a result, the forwarding capability of IP technology becomes a bottleneck of the network development.
Asynchronous transfer mode (ATM) technology has been created from the evolution of network technologies.. It uses labels (particularly, cells) of fixed length and maintains a label table that is much smaller than a routing table. Therefore, compared to IP technology, ATM technology is much more efficient at forwarding packets. ATM technology, however, is a complex protocol with a high cost of deployment, which hinders its widespread popularity and growth.
Traditional IP technology, however, is simple and costs little to deploy. People are eager to use technology that combines the best that IP and ATM technologies have to offer. This has sparked the emergence of MPLS technology.
Initially, MPLS was created to increase forwarding rates. Different from the manner in which packets are routed and forwarded using IP technology, MPLS analyzes a packet header only on the edge of the network rather than at each hop. In this manner, the packet processing time is shortened.
Application-specific integrated circuit (ASIC) technology has now been developed and the routing rate is no longer a bottleneck to the network development. As a result, MPLS no longer has the high-speed forwarding advantages. 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).
MPLS works between the data link layer and the network layer in the TCP/IP protocol stack. It provides the IP layer with connection services and obtains services from the data link layer. MPLS replaces IP forwarding with label switching. A label is a short connection identifier of fixed length that is meaningful to the local end. The label is similar to the ATM virtual path identifier (VPI)/virtual channel identifier (VCI) and the Frame Relay data link connection identifier (DLCI). The label is encapsulated between the data link layer and the network layer.
MPLS is not limited by any specific protocol of the data link layer and is enabled to use any Layer 2 media to transfer packets.
The origin of MPLS is 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.
In fact, the MPLS technology is a tunneling technology but not a service or an application. It supports multiple protocols and services. Moreover, it ensures the security of data transmission.
That's all, I welcome everyone to leave a message and exchange in the comment area!
