PDF《DLSw故障排除：SDLC》

DLSw故障排除:SDLC 目录 简介 先决条件 要求 使用的组件 规则 排除故障SDLC PU类型 常见 SDLC 问题 用于 PU2.

0 设备的会话建立流程示例 用于 PU2.1 设备的会话建立流程示例 Debug SDLC 事件或包 在DLSw期间的SDLC包与PU2.1的SDLC 相关信息 简介 本文帮助您排除故障在网络可能发生,当同步数据链接控制(SDLC) -时的问题附加的终端设备连接 对一个数据中心,例如,在数据链路交换(DLSW). 先决条件 要求 本文档没有任何特定的要求. 使用的组件 本文档不限于特定的软件或硬件版本. 本文档中的信息都是基于特定实验室环境中的设备编写的.本文档中使用的所有设备最初均采用原 始(默认)配置.如果您使用的是真实网络,请确保您已经了解所有命令的潜在影响. 规则 有关文档规则的详细信息,请参阅 Cisco 技术提示规则. 排除故障SDLC 发出show interface serial x命令在路由器开始排除故障SDLC.此命令输出包含也许帮助您找出问题 的信息. Serial1/0 is up, line protocol is up !--- If line is down/down, then check CLOCKING. !--- If line is up/down, then check NRZI_ENCODING. !--- If line is cycling between up/up and up/down, then check DUPLEX. !--- A modem sharing device (MSD) uses full duplex. Hardware is CD2430 in sync mode Description SDLC PU2.1 PRIMARY MTU

1500 bytes, BW

128 Kbit, DLY

20000 usec, rely 255/255, load 1/255 Encapsulation SDLC, loopback not set Router link station role: PRIMARY (DCE) !--- DCE has to provide the clock. It is responsible for raising DCD, CTS, !--- and DSR. Issue the show controllers command to check DTE, DCE, and !--- cable type. Router link station metrics: slow-poll

10 seconds T1 (reply time out)

3000 milliseconds !--- The sdlc t1 command sets the amount of time waited !--- for an acknowledgement to an SDLC frame, where is a !--- numeric value in milliseconds between

1 and

64000 (default is 3000). N1 (max frame size)

12016 bits !--- The sdlc n1 commands sets the maximum size of an !--- incoming frame, where is a numeric value from

1 to

12000 !--- (default is 12000). N2 (retry count)

20 !--- The sdlc n2 command sets the number of times that an !--- SDLC frame is sent before the session is terminated, where !--- is a numeric value between

1 and

255 (default is 20). poll-pause-timer

200 milliseconds !--- Set this with the sdlc poll-pause-timer command, !--- where is a numeric value in milliseconds from

1 to 10000. !--- Set this value to a minimum of

2000 before you run SDLC debugs;

otherwise, !--- you will flood the console with SDLC polling messages. poll-limit-value

1 !--- Set this with the sdlc poll-limit-value command, where !--- is a numeric value from

1 to 10. !--- Use this command on multidrops to determine the number of polls that are !--- dedicated to each secondary device. Higher value allows a single secondary !--- to send more data but can decrease overall secondary servicing efficiency. k (windowsize)

1 modulo

8 !--- Set K with the sdlc k command, where is a !--- numeric value of

1 through

7 (if modulo 7) or

1 through

127 (if modulo 128). !--- rrrz sss0 !--- rrr = Frame number of the block that is expected to be received next !--- (rrrrrrr if modulo 128) !--- z = Poll/Final bit, which may be

0 or 1. !--- sss = Frame number of the block that is expected to be sent next !--- (sssssss if modulo 128) !--- The K value determines how many frames after which the poll bit is set to 1, !--- which indicates that it is the other side???s turn to send. sdlc vmac: 4000.1555.21-- sdlc addr