An E1 Interface of an AR2220 Router Connects to a Remote Cisco Router Through an E1 Link, but Cannot Go Up

Publication Date:  2015-11-19 Views:  715 Downloads:  0
Issue Description
An E1 interface on the 2E1-M card of an AR2220 router connects to an interface on a remote Cisco router through an E1 link provided by the carrier, but cannot go Up physically.

Alarm Information
Run the display controller e1 command on the AR2220 router to check the status of the E1 interface. The command output shows that the physical status of the interface is Down.

<Huawei> display 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 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.

Ping the IP address of the remote Cisco router on the AR2220 router. The ping operation fails.
Handling Process
Step 1 Check the device model and software version. Run the display version and display device commands to check the device version and card status. The command outputs show that the device version is V200R005 and the loading status of the 2E1-M card is normal.

<Huawei> display version
Huawei Versatile Routing Platform Software                                      
VRP (R) software, Version 5.160 (AR2200 V200R005C00)                            
Copyright (C) 2011-2015 HUAWEI TECH CO., LTD
<Huawei> display device
AR2220's Device status:                                                         
Slot  Sub Type             Online   Power     Register      Alarm        Primary
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
3     -   2E1/T1-M         Present  PowerOn   Registered    Normal       NA

Step 2 Ensure that a 120-ohm RJ48-to-DB9 balanced cable is connected to the AR2220 router and the optical transceiver provided by the carrier.

Step 3 Verify that the configuration information is correct.

#
controller E1 3/0/0
using e1
description International Curcuit
undo detect-ais
line-termination 120-ohm
#
interface Serial3/0/0:0
link-protocol hdlc
description International Curcuit
ip address x.x.x.x x.x.x.x
#
return

Step 4 Run the display controller e1 command. The Alarm State field displays the alarm "Receiver alarm state is Loss-of-Signal." A fault may occur on the link provided by the carrier or on the jumper.

<Huawei> display 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

Step 5 Require the carrier to perform a loopback test on the AR2220 router at the optical transceiver side. The test result shows that the physical status of the E1 interface on the AR2220 router is Up, and the Input and Output fields of the serial interface display the same number of packets, indicating that the 2E1-M card status and cable status are normal. Therefore, the fault occurs on the carrier's optical transceiver.

Step 6 Perform a loopback test on the E1 interface of the carrier's optical transceiver. The test result shows that the interface status is Down, indicating that the interface is faulty. Adjust the interface to the correct one, and the fault is rectified.

----End
Root Cause
The E1 interface of the carrier's optical transceiver connected to the AR2220 router is faulty.
Solution
Require the carrier to check the interface of the optical transceiver connected to the AR2220 router. Adjust the interface to the correct one. The fault is rectified.
Suggestions
Check device status and information using commands to locate the fault. Use a correct troubleshooting roadmap, run correct commands, and analyze the corresponding command outputs.

END