论坛站务软件水平考试华为认证计算机等级PMP认证思科认证Photoshop3DMAX编程语言移动开发系统运维产品运营淘宝营销办公软件Ps修图云计算大数据摄影就业

<p style="margin-top: 0px; margin-bottom: 10px; padding: 0px; box-sizing: border-box; color: rgb(51, 51, 51); font-family: &quot;Helvetica Neue&quot;, Helvetica, Arial, sans-serif; white-space: normal; background-color: rgb(255, 255, 255);">　　为帮助考生备考2022年软考<span style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(255, 0, 0);"><span style="margin: 0px; padding: 0px; box-sizing: border-box; font-weight: 700;"><a href="http://www.kokojia.com/package-203.html" target="_blank" style="margin: 0px; padding: 0px; box-sizing: border-box; cursor: pointer; text-decoration-line: none; color: rgb(51, 122, 183); background-color: transparent;"><span style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(255, 0, 0);">网络工程师考试</span></a></span></span>，课课家小编为大家整理了2022年网络工程师考试知识点(四十五)：HDLC，相信对大家备考复习会有帮助。</p><p style="margin-top: 0px; margin-bottom: 10px; padding: 0px; box-sizing: border-box; color: rgb(51, 51, 51); font-family: &quot;Helvetica Neue&quot;, Helvetica, Arial, sans-serif; white-space: normal; background-color: rgb(255, 255, 255);">　　很多考生在备考2022年网络工程师考试，课课家小编为大家整理了2022年网络工程师考试知识点(四十五)：HDLC，供考生备考复习。</p><p style="margin-top: 0px; margin-bottom: 10px; padding: 0px; box-sizing: border-box; color: rgb(51, 51, 51); font-family: &quot;Helvetica Neue&quot;, Helvetica, Arial, sans-serif; white-space: normal; background-color: rgb(255, 255, 255);">　　HDLC是一种面向比特的链路层协议，HDLC帧格式包括标志字段、地址字段、控制字段、数据和校验和。</p><p style="margin-top: 0px; margin-bottom: 10px; padding: 0px; box-sizing: border-box; color: rgb(51, 51, 51); font-family: &quot;Helvetica Neue&quot;, Helvetica, Arial, sans-serif; white-space: normal; background-color: rgb(255, 255, 255);">　　标志字段(01111110)：用于确定帧的起始和结束，以进行帧同步和准确识别长度可变的帧。</p><p style="margin-top: 0px; margin-bottom: 10px; padding: 0px; box-sizing: border-box; color: rgb(51, 51, 51); font-family: &quot;Helvetica Neue&quot;, Helvetica, Arial, sans-serif; white-space: normal; background-color: rgb(255, 255, 255);">　　HDLC采用比特填充法使一个帧中两个标志字段之间不会出现6个连续的1</p><p style="margin-top: 0px; margin-bottom: 10px; padding: 0px; box-sizing: border-box; color: rgb(51, 51, 51); font-family: &quot;Helvetica Neue&quot;, Helvetica, Arial, sans-serif; white-space: normal; background-color: rgb(255, 255, 255);">　　具体做法是：在发送端，在加标志字段之前，先对比特串扫描，若发现5个连续的1，立即在其后加一个0。在接收端收到帧后，去掉头尾的标志字段，对比特串进行扫描，当发现5个连续的1时，立即删除其后的0。</p><p style="margin-top: 0px; margin-bottom: 10px; padding: 0px; box-sizing: border-box; color: rgb(51, 51, 51); font-family: &quot;Helvetica Neue&quot;, Helvetica, Arial, sans-serif; white-space: normal; background-color: rgb(255, 255, 255);">　　默认时，Cisco路由器的串口是采用Cisco HDLC封装的。</p><p style="margin-top: 0px; margin-bottom: 10px; padding: 0px; box-sizing: border-box; color: rgb(51, 51, 51); font-family: &quot;Helvetica Neue&quot;, Helvetica, Arial, sans-serif; white-space: normal; background-color: rgb(255, 255, 255);">　　HDLC的帧类型：定义了承载用户数据的信息帧(I帧)，进行流量和差错控制的管理帧(S帧)和用于链路控制的无编号帧(U帧)三种帧类型。而信息帧除了可以承载用户数据之外，还可以捎带肯定管理信息，当没有足够的信息帧捎带时，则需要发送专门的管理帧来完成。</p><p style="margin-top: 0px; margin-bottom: 10px; padding: 0px; line-height: 26px; color: rgb(51, 51, 51); white-space: normal; box-sizing: border-box; font-family: &quot;Helvetica Neue&quot;, Helvetica, Arial, sans-serif; background-color: rgb(255, 255, 255);">　　&gt;&gt;&gt;&gt;&gt;&gt;点击进入<span style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(255, 0, 0);"><span style="margin: 0px; padding: 0px; box-sizing: border-box; font-weight: 700;"><a href="http://www.kokojia.com/activity-ruankao.html" target="_blank" style="margin: 0px; padding: 0px; cursor: pointer; text-decoration-line: none; color: rgb(51, 122, 183); box-sizing: border-box; background-color: transparent;"><span style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(255, 0, 0);">软考报名专题</span></a></span></span></p><p style="margin-top: 0px; margin-bottom: 10px; padding: 0px; line-height: 26px; color: rgb(51, 51, 51); white-space: normal; box-sizing: border-box; font-family: &quot;Helvetica Neue&quot;, Helvetica, Arial, sans-serif; background-color: rgb(255, 255, 255);">&nbsp;</p><p style="margin-top: 0px; margin-bottom: 10px; padding: 0px; line-height: 26px; color: rgb(51, 51, 51); white-space: normal; box-sizing: border-box; font-family: &quot;Helvetica Neue&quot;, Helvetica, Arial, sans-serif; background-color: rgb(255, 255, 255);"><span style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(255, 0, 0);"><span style="margin: 0px; padding: 0px; box-sizing: border-box; font-weight: 700;"><span style="margin: 0px; padding: 0px; box-sizing: border-box;"><span style="margin: 0px; padding: 0px; box-sizing: border-box;"><span style="margin: 0px; padding: 0px; box-sizing: border-box;"><span style="margin: 0px; padding: 0px; box-sizing: border-box;"><span style="margin: 0px; padding: 0px; box-sizing: border-box;"><span style="margin: 0px; padding: 0px; box-sizing: border-box;"><span style="margin: 0px; padding: 0px; box-sizing: border-box;"><span style="margin: 0px; padding: 0px; box-sizing: border-box;"><span style="margin: 0px; padding: 0px; box-sizing: border-box;"><span style="margin: 0px; padding: 0px; box-sizing: border-box;">　　相关推荐：<a href="http://bbs.kokojia.com/ruankao/89368/" target="_blank" style="margin: 0px; padding: 0px; cursor: pointer; color: rgb(0, 174, 239);">2022年网络工程师考试知识点汇总</a></span></span></span></span></span></span></span></span></span></span></span></span></p><p style="margin-top: 0px; margin-bottom: 10px; padding: 0px; box-sizing: border-box; color: rgb(51, 51, 51); font-family: &quot;Helvetica Neue&quot;, Helvetica, Arial, sans-serif; white-space: normal; background-color: rgb(255, 255, 255);"><br/></p>

论坛站务软件水平考试华为认证计算机等级PMP认证思科认证Photoshop3DMAX编程语言移动开发系统运维产品运营淘宝营销办公软件Ps修图云计算大数据摄影就业