Cisco 585-LRE - 585 LRE Customer Premise Equipment Bridge, Руководство пользователя

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Chapter 4 Monitoring
Check the Dashboard
4-10
User Guide for the Catalyst Express 500 Switches
OL-8122-01
Bandwidth Used Gauge
The Bandwidth Used gauge shows the total percentage of the switch bandwidth
being used. Each bar in the gauge represents 10 percent and does not show
increments that are less than 10 percent. The gauge does not show total bandwidth
under 5 percent.
Data is collected at each 60-second system refresh. For a graph that shows
bandwidth utilization patterns over incremental instances in time (by 60 seconds,
60 minutes, 24 hours, or 14 days), see the
“Bandwidth Utilization Graph” section
on page 4-15 .
The Bandwidth Used gauge changes as the switch experiences the network
activity from devices sending data through the network. As network activity
increases, so does contention between devices to send data through the network.
As you monitor utilization on the switch, note whether the percentage of usage is
what you expect during that given time of network activity. If utilization is high
when you expect it to be low, perhaps a problem exists.
As you monitor the switch, note if the bandwidth utilization is consistently high.
This can mean there is congestion in the network. If the switch reaches its
maximum bandwidth (above 90 percent utilization) and its buffers become full, it
begins to discard the data packets that it receives. Some packet loss in the network
is not considered unusual, and the switch is configured to help recover lost packets
(such as by signaling to other devices to resend data). However, excessive packet
loss can create packet errors, which can degrade overall network performance.
To reduce congestion, consider segmenting the network into subnetworks that are
connected by other switches or routers. Look for other causes, such as faulty
devices or connections, that can also increase bandwidth utilization on the switch.