The emergence of optical transport systems has dramatically increased the raw capacity of optical networks and has enabled a slew of new, sophisticated applications. For example, network-based storage, bandwidth leasing, data mirroring, add/drop multiplexing [ADM], dense wavelength division multiplexing [DWDM], optical cross-connect [OXC], photonic cross-connect [PXC], and multiservice switching platforms are some of the devices that may make up an optical network and are expected to be the main carriers for the growth in data traffic.

The diversity and complexity in managing these devices have been the main driving factors in the evolution and enhancement of the MPLS suite of protocols to provide control for not only packet-based domains, but also time, wavelength, and space domains. GMPLS further extends the suite of IP-based protocols that manage and control the establishment and release of label switched paths (LSP) that traverse any combination of packet, TDM, and optical networks.

An important economic impact of GMPLS is providing the ability to automate network resource management and the service provisioning of end-to-end traffic-engineered paths. Service provisioning has been a manual, lengthy, and costly process—e.g., synchronous optical network (SONET)–based ring networks. To manually provision an end-to-end high-speed connection, a carrier must determine which SONET rings the connection traverses and provision bandwidth on each ring manually. If any ring is at full capacity, the carrier must find an alternative ring path or upgrade the capacity of a ring and propagate the information to all sites manually. These are very time-consuming processes and can take months. The deployment of GMPLS–based nodes allows carriers to automate the provisioning and management of the network and promises to lower the cost of operation by several orders of magnitude (days or even minutes instead of weeks or months).