Multiprotocol label switching and IP. Part I. MPLS VPNs over IP tunnels

Multiprotocol label switching (MPLS) is a tunneling technology used in many service provider networks. The most popular MPLS-enabled application in use today is the MPLS virtual private network, MPLS VPNs were developed to operate over MPLS networks, but they can also run over native IP networks. This offers providers flexibility in network-deployment choices, improved routing system scalability, and greater reach to customers. The key element is the ability to encapsulate MPLS packets in IP tunnels.