Multi-protocol label switching (MPLS), an efficient encapsulation mechanism; uses “Labels” appended to packets for transport of data.  With MPLS, the first time a packet enters the network, it’s assigned to a specific forwarding equivalence class (FEC), indicated by appending a short bit sequence (the label) to the packet.

MPLS network has the ability to handle packets with particular characteristics in a consistent fashion. Packets carrying real-time traffic, such as voice or video, can easily be mapped to low-latency routes across the network.