Alarms occur to interface board of NE40 many times every day.
%Dec 7 18:09:47 2005 CZ-R1-JGDS SRM/1/DEMFail:Slot 15 DEM channel 1 failed!
%Dec 7 18:09:50 2005 CZ-R1-JGDS SRM/5/DEMInure:Slot 15 DEM channel 1 inures!
%Dec 7 21:15:34 2005 CZ-R1-JGDS SRM/1/DEMFail:Slot 15 DEM channel 1 failed!
%Dec 7 21:15:37 2005 CZ-R1-JGDS SRM/5/DEMInure:Slot 15 DEM channel 1 inures!
There are a lot of communication messages on MPU and interface board, resulting in flap of detection message over DEM channel; so the alarm information like above occurs.
NE40 uses distributed forwarding structure. MPU processes protocols, and interface board forwards packets according to forwarding entry advertised by MPU. MPU communicates with the chip-9883 of HUB through 82559, and DEM channel runs above both 82559 and 9883. To verify if the channel is normal, the system will transmit a detection packet every second to test DEM channel. If it fails three times, it prompts an alarm of EM channel failed, and DEM channel inures when the detection is restored. A great deal of channel information on MPU and interface board results in flap of detection for DEM channel, so the alarm like above occurs.