Research On Survivability Of Automatically Switched Optical Network

With the rapid popularization of Internet and application, as well as IP data business explosive growth , all sorts of new business are constantly emerging, such as video on demand, bandwidth rent, VPN, etc. This trend not only enable suppliers to bring in broad market prospects and new profit growth point, but also put forward higher request for transmission network. The network that adopt SDH and WDM technique cannot make fully use of bandwidth and is slow in network configuration as well as complicated in operations. In order to adapt to the needs of the network development, the light layer that based on SDH and WDM is integrated with network intelligence that rest on IP technology. Finally, automatical switched optical network, a new network that is able to connect automatically, is come into being. In the new network, survivability technology restores the network whenever system malfunction happens. The paper focuses on survivability technology of Automatically Switched Optical Network with following research and results:(1)Introduction the three plane functions of ASON, connection mode, and network model. Research on characteristics of ASON survivability technology and its advantages are demonstrated by comparison with survivability of IP network and SDH network. Meanwhile, route module, route mode and route demand is illustrated. Bellman-Ford, Dijkstra and A-Star algorithm, three of most frequently used shortest route algorithms currently, are compared and analyzed.(2)ASON protection and restoration mechanism is studied and several applicable strategies are suggested considering the diversity and flexibility of ASON. Last but not least, strategies that integrate ASON protection and restoration are analyzed. Protection of ASON network domain is studied in the paper as well.(3)Shared risk link group and trail protection mechanism that based on it are introduced in the paper. PRDRA is put forward after analysis of currently widely used CRDRA. The algorithm is simulated and the result shows that it has high performance and stability and enjoys greater route computation success rate and higher resource utilization ratio. However, the success rate that protective path works declines when Business path malfunction. Therefore, for services that has higher requirement for network throughput or lower requirement for service stability, PRDRA protective algorithm is suggested and different performance requirement can be satisfied by adjusting route weight of the algorithm. On the contrary, CRDRA, as the path protective algorithm, is suggested when there is high requirement for service stability.