Research On Backup Path In Supanet

As a new network architecture with high-speed data transfer ability, QoS guarantee is a key point of Single Physical layer User-data transfer & switching Platform Architecture Network (SUPANET). The network resources in SUPANET may fail sometimes, as a result, an efficient and reliable fault recovery mechanism is required in SUPANET.This paper firstly summarizes fault detecting and recovering technologies which are common in the network. Then, SUPANET architecture is briefly introduced. And the deficiencies in the existing SUPANET fault recovery mechanism are analyzed.Then, QoS Negotiation Protocol (QoSNP) is introduced and three message formats which are used in establishing backup virtual path (VP) have been redesigned, so that QoSNP is able to establish backup VP. In addition, the establish methods of global and local backup VP are proposed respectively. To gurantee the protection switch, the author proposes SUPA Auto Protection Switching (APS) protocol. Then the message type, Protocol Data Unit (PDU) format and protocol state machine are designed and the whole process of 1:1 and 1:N mode are illustrated respectively. When two or more working VP fault simultaneously in 1:N mode, backup VP can be used by only one working VP at a time (occupied mode), or shared by many working VP (shared mode).After that, this paper proposed three protection methods for backup VP by multiplexing some fields in Ethernet-oriented Physical Frame (EPF) header. To reduce the packet loss rate and VP switching time, a technology called RollBack fault recovery is proposed, which is based on one of the backup VP protection methods.Finally, this paper use OPNET to simulate the bidirectional 1:1 protection switching, bidirectional 1:2 protection switching and RollBack fault recovery respectively. The simulation results show that SUPA APS protocol is feasible when fault occurs, and both the occupied mode and shared mode have advantages and disadvantages, it depends on the traffic requirement. RollBack fault recovery technology which bases on bidirectional 1:1 protection swithing can make packet loss rate lower and protection switching faster.