Design And Implementation Of EPON Management Agent Based On VxWorks

Driven by the increase of people's need for network information and service, Internet continuously develops. On contrary to the bandwidth upgrade of backbone networks, the bottleneck of speed in access networks becomes more and more serious. Current access technology cannot satisfy the increasing broadband users'requirement. In addition, the application of integrated services such as video on demand (VOD) and network conference requires higher bandwidth ability. Ethernet Passive Optical Networks (EPON), which combines Ethernet characteristics such as simple, pure and low cost, and bandwidth advantage of Passive Optical networks (PON), becomes one of the most promising solutions for broadband access technology.Along with EPON technology progress and its industrialized development, it becomes essential for the deployment and application of EPON in FTTH advance to build the secure and effective EPON management agent system. This project is supported by Chinese 863 plan"Passive Optical Networks based on Gigabit Ethernet", and its subsequentially industrialized programs. The author accomplished the design and implementation of embedded EPON management agent system, which successfully passed through Chinese Telecom's system test on EPON devices. The main contributions of this paper include several points:Theoretical architecture of Simple Network Management Protocol (SNMP) is systematically discussed. Based on the discussion of two-level and three-level SNMP model frameworks, the author points out that SNMP Agent Proxy takes place the key part to realize the combination of unified EPON management system and variety of manage protocol instances. The organization and encoding rules of Structure of Management Information (SMI) and Management Information Base (MIB) are specified, and the SNMP message format and SNMP information processing are demonstrated.The MIB modeling for EPON system is expatiated. Based on the analysis of hardware and embedded software structures of Optical Line Terminal (OLT) and Optical Network Unit (ONU) in EPON, and discussion of activities and service models supported by EPON system, the author designs the MIB models for EPON systems, and specifies the organization and definition of EPON private MIBs. The EPON embedded management agent under VxWorks OS platform is developed. The author specifies the five steps of agent realization, including building SNMP environment platform, compiling the MIB files, developing the MIB access routine, verifying the agent function in virtual simulation environment, and realizing the function in embedded processor platform. Simulation results prove that the EPON management agent is available, and easy to operate and maintain.The functional test and performance evaluation of EPON management agent system is implemented in embedded EPON system. The results prove that the agent system can successfully meet the demands of network device management, traffic and service control, network performance supervisal and fault detection. However, the agent capabilities such as throughputs and latency of the agent need to improve, especially under the variable-binding"walk"operation for large numbered MIB information.Based on the capability analysis of EPON management agent, the author proposed schemes to improve the agent capability, including SNMP message format optimization, memory database instruction and the modularization of EPON MIB platform.