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 Ieee802 . 3ah协议规定使用标准的以太帧作为传送oam信息的载体,但使用特殊的组播目的地址域和类型/长度域,以区别普通的以太数据。由于协议是2004年刚颁布的,所以现有的网络设备很可能不能识别新的oam帧,这就需要在数据链路层对数据包进行捕获和构造。
The sending module realizes the function that the data are sent to the internet from the computer machine a . the network module is in charge of the transportation of the dv data through the internet . in the receiving module , the dv data is received by the computer machine b from the internet . the dv data are redisplayed by the digital equipment in the display module 发送模块把dv格式的数据从主机a发送到因特网上；网络模块是dv格式在因特网上的传输；接收模块是接收端的主机b负责从因特网上接收目的地址为本机的dv数据；显示模块是dv格式数据在数字设备的重现和显示。
Finding a feasible and efficient load balanced strategy for the ultra - scalable multi - plane multi - stage switch architecture is a top of nowadays research . the dissertation proposes a two - stage load balanced scheme for the ultra - scalable multi - plane multi - stage switch architecture based self - routing and non - blocking permutation benes network . the approach uses reasonable and efficient logical queueing strategy and schedule scheme in ingress traffic managers and switch planes to realize the two - stage load balancing of ip traffic which for different destination addresses 本文提出一种适用于基于完全可重排无阻塞benes拓扑构建的多平面多路径(多级)超大容量交换结构的两级负载均衡策略,通过在输入流量管理器和benes交换平面内部实施合理而高效的队列组织调度方法,有效实现了基于不同目的地址的ip流量在两个层次上的负载均衡,较好弥补了ciscocrs - 1系统在平面选择和中间级选择时所采用的简单随机或轮循方案的不足。
Because of the reticular interconnections between smgs , it is impossible that a secondary forwarding happens between gateways , therefore the gateway receiving the forwarded message must be able to determine whether the destination address of the forwarded message belongs to a user covered by the gateway , otherwise an error message must be delivered to the forwarding gateway 由于smg网关之间采用网状互联，网关之间不可能出现二次前转，因此接收前转消息的网关必须能判断前转的消息目的地址是否是本网关覆盖范围的用户，若不是，必须发送出错信息到前转网关。
