The Research,Extension And Implementation Of OAM Protocol In EPON System

Nowadays, requirements of communicating keep growing and applications of Internet develop very fast. As introduced, the amount of Internet user was up to 103 million till the end of June 2005. Though the number of broadband user keeps growing, most consumers, especially those high lever ones are not satisfied with the speed. In addition, some high bandwidth consumming technologies' quickly developpment promotes a higher bandwidth requirement. Ethernet is simplly using and cheapness, and PON is resource economizing and can provide high bandwidth, EPON integrates both of their merits and is supposed to be one of the most important technologies of broadband access.IEEE 802.3ah has been released in June 2004, by work force of IEEE 802.3. At present, lots of companies research and develop EPON, some have successfully developed their own EPON chips and equipments. EPON has come into a integrity and maturity chain of the industry, it's a benefit for EPON technology to be improved and developed, and EPON has taken the head when compete with other technologies.This article analyses the researching background and development of EPON firstly, and comprehensively introduces the key techniques in EPON, and implements MPCP , ONU discovery and distance mearsurement, dynamic bandwidth allocation and OAM function and so on. Then the article studies the structure and function of OAM sublayer in particularly, describes the implemation of OAM functions through the analysation of all sorts of OAMPDU structure. Base on the study and analysis above, it advances the extended protocol of OAM sublayer, it includes the following functions:configuration download, configuration query, event notification, batch configuration download, batch configuration query and file download. Lastly, the article describes the process when fulfilling the extended OAM protocol using software, analyses the defect and the improvement aspect of the prococol.The Extended OAM procotol is based on the implementation of EPON chip, to extend the function of OAM sublayer when developing EPON equipment. The function of the Extended OAM procotol is to provide the interface for developping most of the second layer protocol and equipment test on switch. And the protocol needs consistency(between OLT and ONU), validity and real time performance.