MPLS

Multiprotocol Label Switching (MPLS) is a mechanism in high-performance telecommunications networks that directs data from one network node to the next based on short path labels rather than long network addresses, avoiding complex lookups in a routing table.

 

MPLS (Multiprotocol Label Switching) is and why allowing packets to be forwarded at the Layer 2 (switching) level rather than at the Layer 3 (routing) level is important for Quality of Service (QoS).

Multiprotocol Label Switching (MPLS) is a protocol for speeding up and shaping network traffic flows.

MPLS allows most packets to be forwarded at Layer 2 (the switching level) rather than having to be passed up to Layer 3 (the routing level). Each packet gets labeled on entry into the service provider’s network by the ingress router. All the subsequent routing switches perform packet forwarding based only on those labels—they never look as far as the IP header. Finally, the egress router removes the label(s) and forwards the original IP packet toward its final destination.

 

This diagram illustrates how a simple MPLS network works.
MPLS network diagram