What is the MPLS protocol and how does MPLS work over a computer network? 


Learn About the MPLS protocol.

MPLS is an abbreviation for Multiprotocol Label Switching. It is a network technology that enables faster and more controlled network traffic. It was developed for the first time in 1990. It works over IP and ATM networks. In traditional internet routing, a packet is forwarded from the source to the destination via intermediate routers. While in MPLS, the path is predefined.

What does multiprotocol mean?

All the communication uses network protocols. For example, the world wide web uses HTTP over TCP/IP. The MPLS does not make any changes in the protocol, it just adds an additional header for routing.

Where MPLS is implemented in the network message?

The technology improves the routing performance. Network routers are the nodes that are responsible for routing decisions. MPLS support is added to the routers, by adding an additional header between IP and the data link layer. A router with Multiprotol level switching names as Label Switching Router(LSR).

What MPLS protocol header includes?

A heard includes all the control information that is needed by the protocol to add functionality. The header is standardized by the IETF in RFC 3032. In this section, we will explain all the fields of an MPLS header.

How does MPLS improve speed and security as compared to the traditional IP network?

To begin, let us examine how IP routing works. When you visit a website or use a client that requires an active internet connection, such as Skype. Between your host and the server, there are exchanges of protocol messages. Multiple intermediate routers exist between two entities.

At each router, the destination address in the IP header of the packet is read, and then there is a lookup in the complex routing tables for the next router. If the process keeps repeating till messages reach the destination.

Each lookup introduces a delay, which degrades the performance of any type of real-time communication, such as VoIP. There is no such lookup in MPLS; the next hop is selected based on the label.

How to set up a network for MPLS?

The MPLS network is comprised of a collection of connected routers that support the protocol (LSR). The routers at the network’s boundaries are referred to as ingress or edge routers, while those in the middle are referred to as LSRs. On one side, the edger routers connect to conventional IP-only routers, while on the other, they connect to one or more LSR.

How does MPLS routing work? Step by step with example.

Label switching is how the MPLS protocol network operates. This means that at each hop, a level is examined to determine the next router. The following is a step-by-step procedure for routing.

  • When a packet enters the network via an ingress (or edge) router (from a regular IP router), an MPLS header between the data link and the network layer is added to the packet. The header is leveled with an integer value. What the integer value will be is determined by the policies configured on the router. For instance, there may be distinct levels for VoIP and standard web browsing.
  • The next hop is selected based on the level (there is no lookup for the IP header).
  • The next router replaces the level and forwards the packet to the next router. It will keep repeating till the packet reaches the exit ingress router.
  • The exit router removes the MPLS header (level) and forwards it to the normal router. For the receiving side, it makes no difference if the packet arrives via MPLS or normal internet.