Optical Networking Best Practices Handbook

10.7. DYNAMIC MULTILAYER ROUTING SCHEMES

The explosion of Internet traffic has strengthened the need for high-speed backbone networks. The rate of growth in IP traffic exceeds that of IP packet processing capability. Therefore, the next-generation backbone networks should consist of IP routers with IP packet switching capability and OXCs. Wavelength path switching will be used to reduce IP packet switching loads [7].

GMPLS is being developed in the Internet Engineering Task Force (IETF) [7]. It is an extended version of MPLS. While MPLS was originally developed to control packet-based networks, GMPLS controls several layers, such as IP packet, time-division multiplexing (TDM), wavelength, and optical fiber layers. The GMPLS suite of protocols is expected to support new capabilities and functionalities for an automatically switched optical network (ASON) as defined by the International Telecommunication Union–Telecommunication Standardization Sector (ITU-T) [7]. ASON provides dynamic setup of optical connections, and fast and efficient restoration mechanisms and solutions for automatic topology discovery and network inventory.

NTT has developed a photonic MPLS router that offers both IP/MPLS packet switching and wavelength path switching [7]. Wavelength paths, called lambda LSPs, are set up and released in a distributed manner based on GMPLS. Since the photonic MPLS router has both types of switching capabilities and can handle GMPLS, it enables one to create, in a distributed ...