Design And Implementation Of OAM Performance Monitoring Function In ONT Chip

Recent years, access network technology becomes a hotspot of networkconstruction and application. Since PON (Passive Optical Network) technologysupport integrated services and have maintenance-free ability. PON become themainstream technology in the access network field and is constantly becoming.ONT (Optical Network Terminal) is as an important part in the structure of PON,mainly provide user-side interface for the network, and process the user’s dataservices. Ethernet OAM (Operation， Administration and Maintenance)mechanism becomes a key technology to enhance network management andmaintenance capabilities, is used in the ONT equipment.Many standardization organizations and institutions are working to promotethe development and improvement of the OAM mechanism’s standard, ITU-TY.1731standard contains Performance Monitoring Function and FaultManagement Function. Up to now, the standard is the most comprehensive andcomplete agreement. On the circumstances which the business of ONT chip isnormally processed, the development work of Performance Monitoring Functionis increased. In this paper, based on the the analysis of ITU-T Y.1731standard,the achievement way and the implementation details of Performance MonitoringFunction is analysed and researched deply. In according with the design andimplementation of Performance Monitoring Function, the ONT chip is moreapplicable to the needs of the users. The situation of the link between the OLTequipment and local ONT equipment is more convenience to know.Y.1731is analysed and researched. The packet structure, the informationdomain of the packet and the configured critical information of the processingprocedure in the tests of Performance Monitoring Function are introduced.The overall development and design of Performance Monitoring Function iscarried out. In accordance with the function of each module and the con tactbetween Y.1731protocol processing module and other module in data processingsystem, the location and the function of Y.1731procotol processing module inthe entire data processing module are designed and specified. Y.1731protocolprocessing module is linked with other modules through message passing. Thediscrimination process of the upstream or downstream processing state and teststates is developed. In the overall development environment of the chip, theprocedure which the command line configures and reads parameters is researchedand realized.Performance Monitoring Function is divided into five parts: single-ended ETH-LM(Ethernet-Frame Loss Measurement), double-ended ETH-LM,bidirectional ETH-DM(Ethernet-Frame Delay Measurement), bidirectionalthroughput measurement and unidirectional throughput measurement. In-depthstudy of these tests, the detailed design of these tests is given. The process ofpackets matching MEP and generating the reply packets by the test requestpackets is focused on researching.After introduced the design and the implementation of Y.1731agreement,the test program of the Performance Monitoring Function is depicted. On thebasis of the test environment successfully completing, the test procedures, thetest configure informations and the final testing results are illustrated. The causesof unexpected test results, which created by the link fault, are analysed.This paper is analysed the tests of the Performance Monitoring Function andgives the overall implementation project and the detailed design proposal ofevery test, based on the Y.1731protocol. At last, the performance monitoringfunction is successfully realized and achieved the expected goals. The betterdelivery of this function promotes the widely application of the ONT equipment.