ITU-T E.351

There are many network operators who have implemented multiple networks using different network-layer (layer-3) routing protocols, which include TDM-, ATM-, and/or IP-based technology. Rapid growth of multimedia IP-based services has led in turn to ATM and IP technology being implemented and/or planned for PSTNs. Established routing methods are recommended for application across network types (summarized in Table 1), and include the following: a) E.164/NSAP-based number translation/routing; b) automatic generation of routing tables based on network topology and status; c) automatic update and synchronization of topology databases, d) dynamic route selection; and e) QoS resource management. Signalling and information-exchange requirements needed to support these routing methods are recommended, and include the connectivity management and routing policy parameters summarized in Table 4.