Failed to Make Incoming Calls to the VU Switchboard Through the R2 Trunk at a High Probability
Symptom
Network: User A----PSTN----R2----U1910
Version: V100R001C01SPC900
Fault description: Outer-office user A who makes incoming calls to the eSpace U1910 VU switchboard 10 times through the R2 trunk may fail to hear the VU switchboard prompt tone for eight times.
Possible Cause
- The clock source is not synchronized.
- The eSpace U1910 is not grounded, causing digit collection failure.
- The peer end sends digits abnormally.
- Signaling negotiation fails.
Solution
- Check the clock source configuration. The clock source is synchronized.
- Check the eSpace U1910 grounding status. The eSpace U1910 is grounded properly.
- Dial other intra-office DDI numbers for multiple times as user A. The test result is normal.
- Capture logs on the eSpace U1910. Signaling interaction is normal.
- Request engineers of the
peer end to check processing on the peer end. Processing on the peer end fails
because the interval between the ADRC and ANSWER messages received by the eSpace
U1910 is too short.
- Install the
V100R001C01SPH905 patch and increase the interval between the ADRC and ANSWER
messages. The fault is rectified.
public_sys-resources/icon-note.gif NOTE:
The process of dialing the VU switchboard is different from that of dialing user numbers because the off-hook event is immediately triggered when the VU switchboard is dialed. Therefore, this fault does not occur when user numbers are dialed.
Conclusion and Suggestion
If similar faults occur subsequently, you can refer to this case for troubleshooting.
