1-1hit |
Hisao YAMAMOTO Kenichi MASE Akiya INOUE Masato SUYAMA
Network management technologies based on network-wide real-time control schemes have become significant in ensuring both high throughput and GOS fairness and maintaining high usage of network facilities. The first part discusses the roles of network control schemes in the network resource hierarchy. With respect to the layering concept for network resources, it is clarified as to why each network control scheme should maintain its autonomy in each corresponding network resource layer, as well as cooperate with the other control schemes. Examples of cooperative control are presented to show that both dynamic routing in the circuit layer networks and path assignment control in the path layer networks can mutually compensate each other for any insufficient control. In the second part, an advanced routing scheme called "State- and Time-dependent Routing (STR) " is proposed. The principle of STR is a combination of routing-domain definition on a time-dependent basis and call-level routing on a state-dependent basis. Performance evaluation examples of STR through large-scale call-by-call computer simulations are presented to show its high throughput performance as well as high adaptability to real-time traffic fluctuations. A system configuration example featuring the STR algorithm which is currently under development for use in NTT's transit networks is also shown.