Network: MA5616-MA5680T-Bearer network-MGC
Fault symptom: Subscribers of two MA5616s join in a CENTREX, and in this group, subscribers can communicate with each other by dialing long numbers, but they cannot communicate with each other by dialing short numbers.
1. Check the CENTREX configurations of the MGC. It is found that the CENTREX configurations are correct.
2. Trace signaling streams on the MGC. It is found that digitmaps are normally issued.
3. Check configurations of the MA5616. It is found that configurations are correct.
4. Enable the DBWIN tool on the MA5616 to trace signaling streams. It is found that hook-off, dialing, and connection setup are normal, and the communication is set up normally, but two subscribers cannot hear each other.
5. Ping the media IP address of the peer device from the MA5616. It is found that the ping operation fails. This indicates that signaling streams are transmitted but media streams are not. 6. Check the OLT. It is found that the two MA5616s are connected to the same PON port and are in the same smart VLAN. By default, these two MA5616s are separate.
7. Enable the ARP proxy on the OLT. Then, the media IP addresses of the two MA5616s can be pinged. After testing calls by dialing short numbers in the CENTREX, it is found that calls can be made.
1. The CENTREX of the MGC is incorrectly configured.
2. Digitmaps issued by the MGC do not match numbers.
3. Configurations of the MA5616 are incorrect.
4. Route for transmitting media streams are not reachable.
Calls can be made by dialing long numbers, because all the calls access the transit exchange, and two MxUs are connected through the TG. In this case, there is not a direct route. Compared with long numbers, short numbers do not access the transit exchange, and media streams are forwarded directly in the bearer network. In addition, the route transmitting the media streams between the caller and the callee is unreachable. This causes that a short number can be dialed but the communication fails.