Call Fails on the PRA Trunk

The following faults often occur on the PRA trunk:

• A busy tone is heard when an incomplete called number is dialed.
• A busy tone is heard when a complete called number is dialed.

The possible causes are as follows:

• The clock sources is not configured on the unified gateway.
• The intra-office and outgoing prefixes are not configured.
• The board status is abnormal.
• The trunk circuit status is faulty.
• The trunk link status is faulty.
• The CRC is enabled on one end, but is disabled on the other end.

1. See E1/T1 Trunk Exception whether the clock source is configured.
2. See Logging In to the unified gateway Using the LMT to run the show prefix callcategory basic command to check whether the intra-office and outgoing prefixes are configured.

   Prefix
   
   
   ------------ ---------- ----------------- -------------------- -------------- 
     SubPBXNo     Prefix     CallAttribute     OfficeSelectCode     RegGroupId   
   ------------ ---------- ----------------- -------------------- -------------- 
   0            0213       local             213                  0              
   0            0          inter             65535                0              
   0            2          inter             65535                0              
   
   
   
   ====  Command executed success !  ====

   • If the preceding information is displayed, the intra-office and outgoing prefixes are not configured. Run the config add prefix command to configure the intra-office and outgoing prefixes.
   • If the intra-office and outgoing prefixes are configured, check that there are no conflicting prefixes. If the fault persists, go to the next step.

3. Run the show board command on the unified gateway check the status of the media resource board (value of the State field).
   • If the status is Fault, Check whether the fault is rectified by remove and reinstall, or replace the board. If the fault is rectified, the troubleshooting process is complete. If the fault persists, go to the next step.
   • If the status is OK, go to the next step.

4. Run the show tkc office no officeno command to check the trunk circuits status (the value of the State field).
   • If the status is ISOLATE, run the config cancelisolate board slot slotno command on the unified gateway to cancel board isolation.
   • If the status is FAULT, see Configuring a PRA Trunk to check whether the trunk data is correct.
   • If the status is IDLE, go to the next step.

5. Run the show pralink command to check whether the trunk link status (value of State field). which indicates that the link status is normal.
   • If the status is FAULT, proceed as follows:
     • The network position (value of Position) of one end must match that of the peer device. That is, when one end is the network side, the other end must be the user side. The unified gateway is configured as the user side.
     • The timeslot (value of TS) of PRA links and the timeslot of the peer device must both be 16.

     If the configured is not right, run the config modify pralink linkno linkno slot slot trunkport trunkport position <user|network> ts ts command to modify.

   • If the status is OK, go to the next step.

6. Check whether the RFA indicator light on a board is on.
   • If yes, contact to the peer office's engineers to check whether the CRC is enabled on the peer device.

     If the CRC is enabled on the peer device, run the following command to enable the CRC on the unified gateway.

     • U1910: config modify cvp type type officeno officeno crcflag yes
     • U1930: config modify cvp type type trunkport trunkport officeno officeno crcflag yes
     • U1911/U1960/U1981/U1980: config modify board slot slot type type trunkport trunkport officeno officeno crcflag yes
   • If no, go to the next step.

7. If the fault still persists, collect detailed fault information and related logs by referring to Collecting and Reporting Fault Information and send them to the service provider.