GE MDS entraNET 2400, Техническое руководство

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05-4055A01, Rev. E MDS entraNET Technical Manual 171
The most significant fields are
Retries
,
Retry Errors
,
Receive Errors
, and
Lost Carrier Detected
. If the data values are more than 10% of their sent
and received counterparts, or the
Lost Carrier Detected
value is greater
than a few dozen, there might be trouble with interference, or a loss of
the Ethernet signal. Note that this does not refer to the over-the-air (RF)
carrier, but only to the Ethernet carrier.
When troubleshooting throughput quality issues, a check should also be
made of the
Radio Packet Statistics Screen shown in Figure 3-45 on
Page 81 . This menu provides a review of packet statistics from a radio
link (RF) perspective.
It is also helpful to check the RSSI of incoming signals. If the RSSI
levels in each zone are within a few decibels (dB) of each other, but less
than –90 dBm, then check the aiming of the antenna system.
See “Aiming Directive Antennas for Maximum RSSI” on Page 162 for
details.
NOTE: The average signal level should be –95 dBm or stronger for
reliable performance with an allowance for fade margin.
Another place to look for trouble is in
Packets Received by Zone
. The
packets should be evenly distributed across all zones (1-5% variation).
If they are not, interference in the disparate zones should be suspected.
Blocking these zones can eliminate or reduce harmful interference.
See “Skip Zones Menu” on Page 53 for more information.
When dealing with radio interference troubles, be sure to review A Word
About Radio Interference on Page 150.
Serial Port and Remote Serial Statistics Menu
(See Figure 3-43 on Page 79 for detailed information)
This screen provides top-level information on data exchanges between
the radio serial ports and the network through the wireless and the
Ethernet (data) layers. These include:
You can use this information as an indicator of port activity at the data
and IP levels.
Diagnostic Tools
(See MAINTENANCE AND TOOLS on Page 85)
The AP Maintenance Menu contains a tool that is especially useful to
network technicians—the
PING
utility. Use the
PING
utility to verify the
reachability of Ethernet devices connected to the network.
• Bytes In On Port xxx • Bytes In On Socket xxx
• Bytes Out On Port xxx • Bytes Out On Socket xxx