华为AR2220路由器配置2E1-M板卡连接运营商E1线路，与远端的cisco设备互联，线路联通后端口无法UP。

通过检查端口的状态发现端口物理状态及line protocol状态都是down,本端地址无法正常ping通对端地址。
AKL-DR-WAN-RT-001-E1 3/0/0]dis controller e1 3/0/0
E1 3/0/0 current state : DOWN
Description : Shanghai International Curcuit
Basic Configuration:
  Work Mode is E1 Unframed, Cable type is 75 Ohm unbalanced.
  Frame-format is None, Line Code is Hdb3.
  Source Clock is Slave, Data-coding is Normal.
  Idle code is 7E, Itf type is 7E, Itf number is 4.
  Loopback is Not Set.
Alarm State:
  Receiver alarm state is Loss-of-Signal.
  Transmitter is sending remote alarm.
  Pulse density violation detected.

1. 查看设备的型号及软件版本，display version，display device检查设备的版本及办卡状态，确定版本是V200R005，板卡加载状态正常。
<Huawei> display device
AR2240's Device status:
Slot  Sub Type         Online    Power      Register       Alarm      Primary
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
3   -   2E1          Present   PowerOn    Registered     Normal     NA

2. 确定连接线缆已经连接，运营商的光端机已经连接，线路类型为RJ48线缆转DB9端口的平衡线缆（120欧）。

3. 检查配置信息，确认配置信息正确。
controller E1 3/0/0
using e1
description Shanghai International Curcuit
undo detect-ais
line-termination 120-ohm
#
interface Serial3/0/0:0
link-protocol hdlc
description Shanghai International Curcuit
ip address x.x.x.x x.x.x.x

4. 检查接口信息及log信息,发现E1端口下面有错误告警信息。怀疑是运营商线路或连接跳线故障。
[AKL-DR-WAN-RT-001-E1 3/0/0]dis controller e1 3/0/0
E1 3/0/0 current state : DOWN
Description : International Curcuit
Basic Configuration:
  Work Mode is E1 Unframed, Cable type is 120 Ohm balanced.
  Frame-format is None, Line Code is Hdb3.
  Source Clock is Slave, Data-coding is Normal.
  Idle code is 7E, Itf type is 7E, Itf number is 4.
  Loopback is Not Set.
Alarm State:
  Receiver alarm state is Loss-of-Signal.
  Transmitter is sending remote alarm.
  Pulse density violation detected.
Historical Statistics:
  Data in current interval (567 seconds elapsed):
  37158345 Line Code Violations, 0 Path Code Violations
  567 Slip Secs, 0 Fr Loss Secs, 567 Line Err Secs, 0 Degraded Mins
  567 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 567 Unavail Secs
  Total Data (last 24 hours):
  59117268 Line Code Violations, 0 Path Code Violations
  912 Slip Secs, 53 Fr Loss Secs, 912 Line Err Secs, 0 Degraded Mins
  912 Errored Secs, 0 Bursty Err Secs, 53 Severely Err Secs, 912 Unavail Secs

[AKL-DR-WAN-RT-001-Serial3/0/0:0]dis int s3/0/0:0
Serial3/0/0:0 current state : DOWN
Line protocol current state : DOWN
Description:Shanghai International Curcuit
Route Port,The Maximum Transmit Unit is 1500, Hold timer is 10(sec)
Derived from E1 3/0/0,  Unframed mode,  baudrate is 2048000 bps
Internet Address is x.x.x.x/y
Link layer protocol is nonstandard HDLC
Current system time: 2014-12-23 07:45:48
Last 300 seconds input rate 0 bytes/sec 0 bits/sec 0 packets/sec
Last 300 seconds output rate 0 bytes/sec 0 bits/sec 0 packets/sec
Input: 0 packets, 0 bytes
  Total Error:             0,  No Buffers:              0
  runts:                   0,  Giants:                  0
  CRC:                     0,  Alignments:              0
  Aborts:                  0
Output: 0 packets, 0 bytes
  Total Error:             0,  No Buffers:              0
  Giants:                  0
    Input bandwidth utilization  :    0%
    Output bandwidth utilization :    0%

5. 要求运营商在端口连接侧对跳线打环测试，测试结果显示端口为up，确定板卡和设备运行正常，故障在物理线路侧。
6. 继续在运营商光端机端口打环进行测试，测试结果显示接口为down。确定是运营商光端机端口连接故障，调整端口连接。故障排除。

运营商光端机E1端口连接故障。

通知运营商检查光端机连接端口，调整到正确端口，故障排除。

通过命令逐步检查状态和信息，确定故障根源，建立正确的故障排查思路，运用正确的命令采集相应结果进行分析。