Study The Signaling Of Automatic Switched Optical Network

With optical networks business number dramatically increase, traditional optical network facing serious challenges in terms of network management method, scalability, quality of service, protection and restoration of business and multi-carriers’interoperability. Automatic Switched Optical Network (ASON), a new optical network which has distributed dynamic connection management capabilities and flexible business protection and restoration capability, get more and more attention of academic and engineer.Firstly, paper detailed study ASON’s distributed connection management framework (DCM). DCM, the prototype of all ASON’s distributed management scheme, design the basic steps of how to distributed management. Private Network to Network Interface (PNNI), Constraint Routing Label Distribution Protocol (CR-LDP) and Resource ReSerVation Protocol-Traffic Engineering (RSVP-TE) are there distrbuted management signal protocol of ASON, paper deeply research their develop history, signaling process and applicable scene. For RSVP-TE get more market acceptance and better development prospects, it would be further studied in following paper works.GMPLS extends signaling messages and objects for RSVP-TE. Based on the theoretical analysis of GMPLS RSVP-TE signaling connection handling process, connection status and soft state refresh mechanism, this paper designs the software module. The RSVP-TE module uses a multi-threaded program framework, including six threads with coordination and cooperation:reading interface thread, writing interface thread, sending packets thread, receiving packets thread, unpacking packets thread and timer thread. The RSVP-TE module also uses an ACK answer message and retransmission mechanism for timeout packets to ensure reliable transmission of signaling messages.Following the study of the traditional serial, parallel and quasi-parallel signaling message distribution, a new signalling message distribution method, tree distribution mechanism, has been proposed. Especially, detail the signaling process of the simplest two-part forwarding tree. And finally, this paper design and implement an ASON test platform to simulate the above four signalling message distribution methods. Through simulation results, a conclusion could be drawn, the tree method has shorter connection establish time, lower blocking rate and control overheads than others.