In a network, many boards on the two sets of OSN 3500 equipment in the same cabinet report the COMMUN_FAIL alarm. Engineers query the board version and the reset records but the equipment become slow to respond to the query. At last, the query fails and the board version and reset records cannot be obtained.
The parameters of the COMMUN_FAIL alarm are 0x01 0x00 0x03 0xff 0xff 0xff 0xff.
1. Check the AUX board. It is found that the COM port is not connected to any cable but the two EXT ports of the subracks are connected.
2. Because the two subracks are both main subracks, the EXT ports need not be connected. Disconnect the cable from the EXT ports. Then, the alarm is cleared and the equipment can normally respond to the operation commands.
1. According to the analysis of the alarm parameter, the COMMUN_FAIL alarm is reported because inter-board Ethernet communication is abnormal.
2. Because the two subracks encounter the same problem, connections between the two subracks, especially the connection between the COM ports and EXT ports of the AUX boards corresponding to the LANSWITCH, should be carefully checked.
The EXT port is used for the communication between the OSN 3500 extended subrack and the main subrack. In the case of two main subracks, the EXT port should not be connected. Otherwise, the communication of the LANSWITCH bus is abnormal because the internal IP addresses of the boards in the same slots on the two subracks are the same.