Specifications

9-48
Cisco ONS 15454 Installation and Operations Guide, R3.2
March 2002
Chapter 9 Ethernet Operation
G1000-4 Performance and Maintenance Screens
9.8.3.2 Line Utilization Window
The Line Utilization window shows the percentage of line, or port, bandwidth used and the percentage
used in the past. Display the CTC card view and click the Performance and Utilization tabs to display
the screen. From the Interval menu, choose a time segment interval. Valid intervals are 1 minute, 15
minutes, 1 hour, and 1 day. Press Refresh to update the data.
9.8.3.3 E Series Utilization Formula
The utilization screen numbers may differ from the numbers encountered on an Ethernet test set. The
line utilization numbers express the average of ingress and egress traffic as a percentage of the total
capacity. Line utilization is calculated with the following formula: (InOctets + OutOctets)*8
bits/octets/100/ intervals*(maxRate*2). Intervals is defined in seconds. maxRate is defined by raw
bits/second in one direction for the circuit. maxRate is multiplied by 2 in the denominator to get the raw
bit rate in both directions.
This formula does not take into account the HDLC headers, SONET header and inter-frame gap. This
means that the line utilization numbers will not reach 100%. It also means that smaller packet sizes will
result in lower utilization figures.
Note Line utilization numbers express the average of ingress and egress traffic as a percentage of capacity.
9.8.3.4 History Window
The Ethernet History screen lists past Ethernet statistics. At the CTC card view, click the Performance
tab and History subtab to view the screen. Choose the appropriate port from the Line menu and the
appropriate interval from the Interval menu. Press Refresh to update the data. Table 9-14 defines the
listed parameters.
Tx Pause Frames (G series only) Number of transmitted 802.3x pause frames.
Rx Pkts Dropped Internal
Congestion (G series only)
Number of received packets dropped due to overflow in G1000-4
frame buffer.
Tx Pkts Dropped Internal
Congestion (G series only)
Number of transmit que drops due to drops in G1000-4 frame buffer.
Table 9-14 Ethernet Parameters
Parameter Meaning
Table 9-15 maxRate for STS circuits
STS-1 51840000
STS-3c 155000000
STS-6c 311000000
STS-12c 622000000