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公开(公告)号:US4493021A
公开(公告)日:1985-01-08
申请号:US250585
申请日:1981-04-03
摘要: A local area network is provided for a plurality of autonomous computers (10) which operate at different rates and under different protocols coupled by network bus adapters (12) to a global bus (14). A host computer (HC) divides a message file to be transmitted into blocks, each with a header that includes a data type identifier and a trailer. The associated network bus adapter (NBA) then divides the data into packets, each with a header to which a transport header and trailer is added with frame type code which specifies one of three modes of addressing in the transmission of data, namely a physical address mode for computer to computer transmission using two bytes for source and destination addresses, a logical address mode and a data type mode. In the logical address mode, one of the two addressing bytes contains a logical channel number (LCN) established between the transmitting and one or more receiving computers. In the data type mode, one of the addressing bytes contains a code identifying the type of data. Every NBA initialized to accept specified types of data will automatically accept all data of the types it is conditioned to accept. Protocol handling is carried out by a module in each NBA.
摘要翻译: 为多个自主计算机(10)提供局域网,其以不同的速率操作,并且在由网络总线适配器(12)耦合到全局总线(14)的不同协议下操作。 主机(HC)将要发送的消息文件划分成块,每个块具有包括数据类型标识符和预告片的标题。 相关联的网络总线适配器(NBA)然后将数据分成数据包,每个数据包都带有一个标题,传输头部和尾部加到该标题上,帧类型代码指定了传输数据的三种寻址模式之一,即物理地址 用于计算机到计算机传输的模式,使用用于源和目的地址的两个字节,逻辑地址模式和数据类型模式。 在逻辑地址模式中,两个寻址字节中的一个包含在发送和一个或多个接收计算机之间建立的逻辑信道号(LCN)。 在数据类型模式中,寻址字节之一包含标识数据类型的代码。 每个初始化为接受指定类型的数据的NBA将自动接受其接受的类型的所有数据。 协议处理由每个NBA中的模块执行。