Most services borne by transport networks have been transitioned away from Time Division Multiplexing (TDM) towards IP-based. New technology is therefore required to effectively transport packet services. Multiprotocol Label Switching Transport Profile (MPLS-TP) is such a technology which is connection-oriented, capable of multiservice adaptation, and has a flexible label forwarding mechanism. This paper analyzes the characteristics of MPLS-TP, and introduces its latest standardization development. Key issues including data forwarding plane, service adaptation, and label forwarding mechanism are discussed, as well as service implementation of Virtual Private Network (VPN) based on dual-label transport. MPLS-TP applications are summarized in conclusion.

The fast development of IP services forces the traffic flow in the networks to move gradually from Time Division Multiplexing (TDM ) services to packet data services. To adapt to the change, low-cost Ethernet technologies are introduced into the Metropolitan Area Network (MAN ). Ring network control protocols and ring network protection technologies are applied to guarantee manageability and reliability required in the telecom networks. The Ethernet Ring Protection (ERP ) and Resilient Packet Ring (RPR ) are two different ring protection technologies. The Transport Multi-Protocol Label Switching (T-MPLS ) network uses the T-MPLS Shared Protection Ring (TM-SPRing ) technology to provide ring protection. Carriers can expand the protection as needed and use appropriate ring technologies to meet the requirements of Carrier Ethernet (CE ).