文档介绍：摘要
数据通信是20世纪50年代随着计算机技术和通信技术的迅速发展,以及两者之间的相互渗透与结合而兴起的一种新的通信方式,它是计算机和通信相结合的产物。随着计算机技术的广泛普及与计算机远程信息处理应用的发展,数据通信应运而生,它实现了计算机与计算机之间,计算机与终端之间的传递。由于不同业务需求的变化及通信技术的发展使得数据通信经过了不同的发展历程。数据链路层作为网络通信的基础,它所涉及到的数据通信技术是建立计算机网络的重要基础。基于实现数据链层的差错控制和流量控制,产生了一系列的协议。
停等协议是数据链路层最基本的链路层协议但为克服信道噪声引起的帧传送错误,可在数据链路层采用面向连接的协议,以保证向上层用户提供可靠交付服务。其中采用停止等待ARQ协议是最简单的,它适用于许多特定场合。协议通过在收发双方之间对每帧的校验确认和出错重传机制,实现数据的可靠交付。协议通过在收发双方之间对每帧的校验确认和出错重传机制,实现数据的可靠交付。
结果表明:传输可靠性HDLC中所有的帧(包括响应帧)都有FCS,在BSC的监控报文中只有字符校验能力而无块校验能力。HDLC中的帧按窗口序号顺序编号,BSC的数据块不编号。HDLC的传输可靠性比BSC高。
关键词:数据链路层;停等协议;数据通信;帧
Abstract
munication is the 1950s along with puter technology municati on technology, and the rapid development of the mutual infiltration and between the rise of c ombining a munication mode, it bined with puter munication of the product. Along with puter technology with the popularization puter rem ote information processing applications development, munication arises at the histor ic moment, it achieved between puter and puter, puter and the termina ls of transfer between. Due to the different business demand changes munication tech nology development allows munication through the different development process. T he data link layer munication foundation, it involved in munication te chnology is an important basis of setting up work. Based on the data realization chain layer error-controlling and flow control, produced a series of agreements.
Stop data link layer such agreement is the most fundamental link layer protocol but to ov e channel noise transmission error caused, can be in the frame of the data link layer usin g connectionless protocol, in order to assure the upper provide reliable delivery service. Use a
mong them to stop waiting ARQ agreement is the most simple, it is used in many occasions. Agreement between the two sides in transceiver to through the confirmation and each frame c alibration error retransmission mechanism, realize the data reliable delivery. Agreement betw een the two sides in transceiver to