MPLS : Multi Protocol Label Switching

Multi Protocol Label Switching

Multiprotocol Label Switching (abbreviated as MPLS) is a packet forwarding technology on high-speed backbone network. The principle works combine some advantages of circuit-switched communication systems and packet-switched technology that gave birth to a better than both. Previously, the packets are forwarded by routing protocols such as OSPF, IS-IS, BGP, or EGP. Routing protocols are on the network layer (third) in the OSI system, while MPLS is between the second and third layers.

 
The working principle of MPLS is to combine the speed of switching at layer 2 with routing capabilities and scalability of layer 3. The way it works is by slipping between the header label at layer 2 and layer 3 on packets forwarded. Produced by Label Label-Switching Router which acts as a liaison with networks outside the MPLS network. The label contains further information destination node where the packet should be sent. The packet is forwarded to the next node, the node is the label the package will be released and given a new label that contains the next destination. Packets are forwarded in a path called LSP (Label Switching Path).

MPLS Components :

• Label Switched Path (LSP): A path through one or a series of LSRs where the packets are forwarded by swapping labels from an MPLS node to another MPLS node. 
• Label Switching Router: MPLS nodes that are capable of forwarding packets Layer-3 
• MPLS Edge Node or Label Edge Router (LER): MPLS node that connects an MPLS domain with nodes that are outside the MPLS domain 
• MPLS egress node : MPLS nodes that regulate traffic when leaving the MPLS domain 
• MPLS ingress Node : MPLS nodes that regulate traffic when going into the MPLS domain 
• MPLS label : a label that is placed as an MPLS header 
• MPLS node : a node that is running MPLS. MPLS node is a control protocol that will forward packets based on labels.