This alarm is reported when the IP clock link connected to the clock server fails.

Parameters

Parameter Name	Parameter Description
Link No.	Link number of the faulty IP clock

Impact on the System

Alarm Severity	Alarm Impact
Minor	The base station fails to synchronize to the IP clock. The system clock may be unusable if the base station does not obtain the clock reference for a long time. As a result, the quality of services of the base station decreases, resulting in handover failure and call drop. In certain cases, the base station cannot provide services.

System Actions

If other clock references are available and the system clock works in auto mode, the system automatically switches to the clock reference with the highest priority.

Possible Causes

• The port used for the IP clock link is faulty.
• The IPCLK link is incorrectly configured.
• The route from the NE to the clock server is not configured.
• The route from the NE to the clock server is unreachable.
• The main control board hardware is faulty.

Procedure

1. Check for the correlated alarm on the M2000.
   1. Check for the correlated alarm of the port that bears the IPCLK link on the M2000.

      
      

      26220 Transmission Optical Module Fault

      26221 Transmission Optical Module Not In Position

      26222 Transmission Optical Interface Error

      26223 Transmission Optical Interface Performance Degraded

      25880 Ethernet Link Fault

      25881 MAC Excessive Frame Error Rate

      
      

      
      

      25885 IP Address Conflict

      Y => The correlated alarm exists. Go to sub-step b.

      N => The correlated alarm does not exist. Go to step 2.

      
      

   2. Clear the correlated alarm according to the relevant handling suggestions.

      
      

      Check whether the alarm is cleared.

      Y => The alarm is cleared. No further action is required.

      N => The alarm is not cleared. Go to step 2.

      
      

2. Check the IPCLK configuration on the M2000.
   1. Run the MML command LST BTSIPCLKPARA to check whether the IP address of the clock server and the IPCLK type are consistent with the network planning.

      
      

      Y => The IP address of the clock server and the IPCLK type are consistent with the network planning. Go to step 3.

      N => The IP address of the clock server and the IPCLK type are inconsistent with the network planning. Go to sub-step b.

      
      

   2. Run the MML command SET BTSIPCLKPARA to change the configuration of IPCLK link.

      
      

      Check whether the alarm is cleared.

      Y => The alarm is cleared. No further action is required.

      N => The alarm is not cleared. Go to step 3.

      
      

3. Check the configuration of route from the NE to the clock server on the M2000Run the MML command LST BTSIPRT to query all the current routes. Check whether an IP route connecting the peer clock server exists.

   1. 
      

      Y => There is an IP route connecting the peer clock server. Go to step 4.

      N => There is no IP route connecting the peer clock server. Go to sub-step b.

      
      

   2. Run the MML command ADD BTSIPRT to add an IP route connecting the peer clock server. Then, wait for at least five minutes.

      
      

      Check whether the alarm is cleared.

      Y => The alarm is cleared. No further action is required.

      N => The alarm is not cleared. Go to step 4.

      
      

4. Check the reachability of route from the NE to the clock server on the M2000.
   1. Run the MML command PING IP to check whether the route from the NE to the clock server is reachable.

      
      

      Y => The route is reachable. Go to sub-step d.

      N => The route is unreachable. Go to sub-step b.

      
      

   2. Contact the maintenance engineer responsible for the clock server to rectify the fault on the clock server.

      
      

      Check whether the alarm is cleared.

      Y => The alarm is cleared. No further action is required.

      N => The alarm is not cleared. Go to sub-step c.

      
      

   3. Contact the maintenance engineer responsible for the routing device to rectify the route fault.

      
      

      Check whether the alarm is cleared.

      Y => The alarm is cleared. No further action is required.

      N => The alarm is not cleared. Go to sub-step d.

      
      

   4. Contact the maintenance engineer responsible for the clock server to troubleshoot the improper processes of the clock server.

      
      

      Check whether the alarm is cleared.

      Y => The alarm is cleared. No further action is required.

      N => The alarm is not cleared. Go to step 5.

      
      

5. Remove the main control board and properly reinstall it on site.
   1. Note: Removing or reinstalling the main control board disrupts all the ongoing services of the base station. Therefore, perform this operation in low-traffic hours. Remove and reinstall the main control board.

      
      

      Check whether the alarm is cleared.

      Y => The alarm is cleared. No further action is required.

      N => The alarm is not cleared. Go to step 6.

      
      

6. Replace the main control board on site.
   1. Note: Replacing the main control board disrupts all the ongoing services of the base station. Therefore, perform this operation in low-traffic hours. The base station software upgrade may be required during board replacement, so the correct software version should be ready for use in advance.

      
      

      Replace the main control board.

      Check whether the alarm is cleared.

      Y => The alarm is cleared. No further action is required.

      N => The alarm is not cleared. Reinstall the original main control board.

Well structured & well compiled even though a bit lengthy.

useful document, thanks