MPLS Transport Profile (MPLS-TP)
The rise of bandwidth-hungry applications such as Triple Play and IP Video, coupled with the pressure to minimize the cost per bit, is forcing carriers to rethink their transport infrastructure. In light of the rise of packet-based services, the natural transition is to move from a circuit-based transport to a packet-based one, to take advantage of the flexibility and cost benefits of packet-switching technology. In this context, a transport profile of Multi-Protocol Label Switching called MPLS-TP is currently being developed, with the goal of forming the basis for next-generation packet transport networks.
This chapter discusses the business drivers behind this development, the requirements for making MPLS transport-friendly, and the enhancements to the MPLS protocol suite that are in the process of being defined by the IETF. After describing the technology, we look at some deployment scenarios, and finally we examine some of the common misconceptions about MPLS-TP.
17.2 THE BUSINESS DRIVERS
The first communication services were circuit based, for example, the Public Switched Telephone Network (PSTN), leased lines and Frame Relay and ATM virtual circuits. For this reason, a circuit based digital multiplexing and transport infrastructure was developed to serve them, in the shape of SONET/SDH.1 As well as serving as the lowest common denominator over which an operator transported all of its own services, it was also the primary ...