MPLS (Multi Protocol Label Switching) is a technique that is used for the routing of network packets. It is called a Multiprotocol as it supports multiple protocols like Internet Protocol (IP), Asynchronous Transport Mode (ATM) and Frame Relay protocols. Moreover, in MPLS technique the network packet forwarding is done based on the label present on the packet, that’s why it is called Label Switching.

MPLS is good for point-to-point connections, even where the points are distant from each other and routed over multiple hops. It’s easier to give bandwidth guarantees for MPLS than for IP.

Major difference between MPLS and traditional routing:

• In MPLS, the switching of traffic is based on the labels assigned to the network packets. While in traditional routing, it is based on destination IP address.
• In MPLS, a fixed and dedicated path is established for the routing of network packets and this path is known as the LSP (Label Switched Path). While in traditional routing, no such defined path is formed.
• MPLS Builds LFIB (Label Forwarding Information Base) table using LDP protocol. While in traditional routing, the information is stored in routing table.
• In MPLS technology, the labels are inserted between layer 2 and layer 3 of TCP/IP model hence it lies at layer 2.5. While IP routing is a layer 3 protocol.
• MPLS is much faster than traditional IP Routing, because it is based on the concept of the label to allow forwarding of packets. This type of forwarding is more efficient as it avoids overloading the CPU.
• Traditional routing performs routing decision based on IP header, MPLS considers MPLS header with packets and hence takes all forwarding decisions based on the MPLS header, unlike traditional routing.

Both MPLS and IP can carry non-IP traffic, but MPLS can do it a little “closer to the metal” than IP can.