Specifications

9-45
Cisco ONS 15454 Installation and Operations Guide, R3.2
March 2002
Chapter 9 Ethernet Operation
G1000-4 Performance and Maintenance Screens
Note The HDLC errors counter should not be used to count the number of frames dropped due to HDLC errors
as each frame can get fragmented into several smaller frames during HDLC error conditions and
spurious HDLC frames can also generate. If these counters are incrementing at a time when there should
be no SONET path problems that may indicate a problem with the quality of the SONET path. For
example, a SONET protection switch causes a set of HLDC errors to generate. The actual values of these
counters is less relevant than the fact they are changing.
9.8.1.2 Utilization Window
The Utilization subtab shows the percentage of current and past line bandwidth used by the Ethernet
ports. 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.
Note The G Series card does not display statistics on the Trunk Utilization screen, since the G Series card is
not a layer two device or switch. The E Series cards is a layer two device or switch and supports the
Trunk Utilization screen. The Trunk Utilization screen is similar to the Line Utilization screen, but Trunk
Utilization shows the percentage of circuit bandwidth used rather than the percentage of line bandwidth.
9.8.1.3 G Series Utilization Formula
The utilization screen numbers may differ from the numbers encountered on an Ethernet test set. The G
series 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*100/
(intervals*maxRate). The interval is defined in seconds. maxRate is defined by raw bits/second in one
direction for the Ethernet port (i.e. 1 Gbps). maxRate is multiplied by 2 in the denominator to determine
the raw bit rate in both directions.
Rx Runts The total number of frames received that are less than 64
bytes in length and have a CRC error.
Rx Giants Number of packets received that are greater than 1548 bytes
in length
Rx Pause Frames (G series
only)
Number of received Ethernet 802.3x pause frames
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 queue drops due to drops in the G1000-4
frame buffer
HDLC errors (G series only) HDLC errors received from SONET/SDH (See note)
Table 9-12 Ethernet Parameters (continued)
Parameter Meaning