TABLE OF CONTENTS Although this book is about Generalized Multiprotocol Label Switching (GMPLS), it is useful to spend this first chapter describing the concepts of Multiprotocol Label Switching (MPLS). Those readers who are already familiar with MPLS may wish to skip this chapter.
MPLS is a data forwarding technology for use in packet networks that was developed by the Internet Engineering Task Force (IETF) building on several technologies invented by different companies. It relies on labeling each packet with a short, unique identifier (or label) that each router can use to determine the next hop for the data packet. It turns out (see Chapter 3) that the same conceptual process used to determine how to forward MPLS packets can also be used in non- packet technologies. At the same time, many of the protocols used to install the forwarding rules at MPLS routers are easily extended to provide data forwarding control in non-packet networks. Thus, the fundamentals of MPLS are an important foundation for Generalized MPLS and are a cornerstone for this book.
MPLS has its roots in several IP packet switching technologies under development in the early and mid 1990s. In 1996 the IETF started to pull the threads together, and in 1997 the MPLS Working Group was formed to standardize protocols and approaches for MPLS.
IP packet switching is the process of forwarding data packets within the network, based on some tag or identifier associated with each packet. In some senses, traditional IP routing is a form of...
