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Calculating packet loss in Example 3

To calculate packet loss for a routed PVC in Example 3, perform these tasks.

1. Display the values for IN_FRAME_UNICAST on the ingress Ethernet port, and the values for OUT_FRAME, OUT_FRAME, and OUTPKTS on the egress ATM port:
• The ingress Ethernet ARU counter records the number of unicast packets -- IN_FRAME_UNICAST -- sent from the Ethernet port to the ATM port through the switch fabric. To display this number, in the CLI, enter this command:

show port stats routing <ethernet port>

• The egress ATM ARU counter records the number of frames
  -- OUT_FRAME -- that are received from the Ethernet port. To display this number, in the CLI, enter this command:

show port stats routing <atm port>

• The egress ACC CPU counter records the number of unicast packets -- OutUcastPkts -- forwarded to the ATM port. To display this number, in the CLI, enter this command:

show atm elan <elan number>

• The egress SAR counter records the number of packets -- OUTPKTS -- sent out the ATM port. To display this number, in the CLI, enter this command:

show port stats atmp <atm port>

2. The number of packets lost is approximately the difference between the IN_FRAME_UNICAST value and the OUT_FRAME value.
3. The difference between the OUT_FRAME value and the OutUcastPkts value should be approximately the same as the value of the OutDiscards. To display the value for OutDiscards enter the following command:

show atm elan <elan number> output