The world is moving towards packet-based transport networks, primarily because all of the applications and services that use these networks are packet-based, and a packet-based transport network is best suited for carrying packets. However, a large number of current transport networks have been built using circuit-switched time-division multiplexing (TDM) technologies such as T1/E1 and SoNET/SDH. Before these networks can be migrated to packet-based technologies such as IP/MPLS, the packet-based technologies need to be enhanced to provide equivalency with legacy networks, both in terms of functionality and manageability.MPLS, which has been a widely successful, connection oriented, packet transport technology, has been production-hardened in thousands of networks worldwide and is ideally suited for packet-based transport networks.. A significant number of service providers have already moved their core networks to MPLS, and many would like to converge their next-generation access, aggregation, and core networks to MPLS as well. However, for this migration to take place, a few enhancements to the MPLS protocol suite are needed to provide functionality and manageability that matches the current circuit-switched transport networks.GMPLS was an evolutionary technology which was developed after the success of MPLS in packet-switched networks. Traditional MPLS was designed to carry Layer 3 IP traffic by establishing IP-based paths and associating these paths with arbitrarily assigned labels. GMPLS extends the functionality of MPLS to encompass label switching for TDM (e.g., SoNET/SDH, PDH), wavelength (lambdas), and spatial switching (e.g., incoming port or fiber to outgoing port or fiber) devices.
đang được dịch, vui lòng đợi..
