Epon Systems Oam Software Module To Achieve

In recent years, with the explosive growth of communication industry, network transmission ability has been improved a lot. Backbone network and high speed LAN are expected to be continuously updated with increasing requests for bandwidth of users. However, the access network connecting backbone network and local customer network becomes the bottleneck of the whole network. Although current broadband access methods, such as xDSL, HFC and cable modem, have provided higher bandwidth and are widely used; they still can't satisfy users'needs, also can't provide enough bandwidth and QoS for new networks'services, such as video meeting, VOD, VOIP and so on. Considering Ethernet and optical network are very popular network with low cost and high bandwidth, consequently, EPON system, which is a passive optical network based on Ethernet, has become one of the most promising technologies in the next generation broadband access network. In 2004, EFM, the 802.3 task group, issued the standard for EPON, IEEE 802.3ah.EPON is mainly composed of three parts, the OLT, ODN and ONU. It deploys optical access lines between an optical line terminator (OLT) and multiple optical network units (ONU). OLT, which provides network access to ONUs is located in CO (central office) side. ONUs which are responsible to send user data to OLT and receive internet data from OLT are located in customer side. Because Ethernet is design to be a simple user network, not access network, so EFM need adding a suite of OAM (Operations,Administation,Maintenance)protocols to achieve the network management goal. The new OAM protocols should have basic management regulations including link state testing, fault alert, loop back etc.In this paper, we implement OAM protocols in both OLT and ONU by adding OAM software function block. Nowadays, embedded system design becomes a trend in electronic field, so we choose C language and Linux for implementing the software programming. EFM use ordinary Ethernet frame to transport OAM information but special destination address and type code field, considering EPON protocols were standarded last year, most of the network device may not recognize the OAM frame above data link layer, so we use Linux access link layer method to construct/capture OAM frame at L2.My research areas are: 1.IEEE 802.3ah protocol research and function block partition, mainly in OAM block. 2. Linux access data link method, libpcap and libnet. 3. Analyse the Linux kernel filtering mechanism (BPF). 4. NAT and its implement.Through the research, following techniques have been obtained: programming in...