Line Utilization Window; Utilization Formula; History Window; Ethernet Maintenance Screen - Cisco ONS 15327 User Documentation

Spanning Tree (IEEE 802.1D)

9.6.5.2 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 window. 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.

9.6.5.3 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 are 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.
Table 9-8
Circuit
STS-1
STS-3c
STS-6c
STS-12c
This formula does not take into account the HDLC headers, SONET header, and inter-frame gap. This
means that the line utilization numbers do not reach 100 percent. It also means that smaller packet sizes
result in lower utilization figures.
Note Line utilization numbers express the average of ingress and egress traffic as a percentage of capacity.

9.6.5.4 History Window

The Ethernet History window lists past Ethernet statistics. At the CTC card view, click the Performance
tab and History subtab to view the window. Choose the appropriate port from the Line menu and the
appropriate interval from the Interval menu. Press Refresh to update the data.

9.6.6 Ethernet Maintenance Screen

Display an Ethernet card in CTC card view and choose the Maintenance tab to display MAC address and
bandwidth information.

9.6.6.1 MAC Table

A MAC address is a hardware address that physically identifies a network device. The ONS 15327 MAC
table, also known as the MAC forwarding table, allows you to see all of the MAC addresses attached to
the enabled ports of an Ethernet card or an Ethernet Group. This includes the MAC address of the
Cisco ONS 15327 User Documentation, R3.3
9-30
maxRate for STS Circuits
maxRate
51840000 bps
155000000 bps
311000000 bps
622000000 bps
Chapter 9 Ethernet Operation
June 2002