1. Check the CPU of all devices, and they are normal.
2. Ping the AG from NE40-1, and the delay is about 2-3 ms and there is no packet loss.
3. Ping the UMG from NE40-1, and the delay is instable and there is packet loss. You need locate the fault between the UMG and the NE40.
Perform the following tests.
4. Switch the service on the UMG to the slave link. Ping the UMG from NE40-2, and there is packet loss.
To further locate the loss, do as follows:
Perform port mirroring on the connected interface of the NE40 and UMG and capture packets.
5. When the NE40 pings the UMG and packet loss occurs, the NE40 sends a request packet. The NE40, however, does not receive a reply packet of the UMG.
6. When the UMG pings the NE40, the NE40 receives a request packet of the UMG and sends a reply packet to the UMG, but packet loss occurs on the UMG. Packets may be discarded by the UMG.
7. Change the UMG to the S3928 (use the optical module of the UMG), assign the network segment address of the UMG, and simulate the UMG.
8. Ping the S3928 from the NE40, and the delay is about 3-4 ms and there is no packet loss. The UMG discards packets.
9. Change slots 14 and 15 of the UMG to slots 12 and 13 and perform the test. Voice services are not interrupted for a long time. The R&D confirms that the hardware in slots 14 and 15 fails.