MPLS

Traditional IP routing has several well-known limitations, ranging from scalability issues to poor support of traffic engineering and poor integration with L2 backbones already existing in large service provider networks.MPLS was created to combine the benefits of connectionless L3 routing and forwarding with connection-oriented L2 forwarding. MPLS clearly separates the control plane, where L3 routing protocols establish the paths used for packet forwarding, and the data plane, where L2 label switched paths forward data packets across the MPLS infrastructure. MPLS also simplifies per-hop data forwarding, where it replaces the L3 lookup function performed in traditional routers with simpler label swapping.Decoupling of control plane from forwarding has lead to many applications like:MPLS-VPN's, MPLS-TE, MPLS-QOS, MPLS-Unicast & Multicast forwarding.