3Com DSA-3CV1001-02 service manual Nic

Using a PC Terminal Emulator to Solve Problems 75

Ethernet Traffic The normal frame counters indicate traffic between the VCN AP and user

Counts PC. Some errored frame counters indicate fatal errors, requiring replacement of the VCN AP, Ethernet cable or the user’s PC Network Interface Card (NIC).

The following table depicts normal count indications of the Ethernet traffic counters and probable causes for abnormal indications.

Table 11 Ethernet Traffic Counters

Counter	Counts the Frames	Normal Count	Abnormal Count
			Indicates
Tx frame	Sent via the Ethernet	Increases as traffic is	No data transmitted;
	Port.	generated	hardware problem:
			■ VCN AP Tx channel
			■	User Ethernet cable
			■	No VCN AP
				connection
Rx frame	Received via the	Increases as traffic is	No data received;
	Ethernet port.	generated	hardware problem:
			■ VCN AP Rx channel
			■	User Ethernet cable
			■	No VCN AP
				connection
Rx collision	The VCN AP was	Zero or steady. For	VCN AP port hardware
	unable to receive	non-zero count,	failure.
	due to collisions on	reset the counter
	the line	and wait a
		reasonable period
		of time to check for
		no significant
		increase.
CRC error,	Containing receive	Zero	Hardware failure: VCN
overrun,	fatal errors.		AP, Ethernet cable or PC
Alignment			NIC
error, frame
too long,

frame too short

HDLC Traffic Counts Normal frame counts indicate traffic between the VCN AP and the VCN AC. Some errored frame counters indicate fatal errors, requiring replacement of the VCN AP (failure between the analog front-end section and the CPU section), or handling of environmental noise over the line.