3Com OfficeConnect 3C857, User Manual

Page: 78 / 120

78 C
HAPTER
6: T
ROUBLESHOOTING
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Ensure that the Wireless Clients are using the same SSID or Service
Area Name as the Gateway. The SSID is case-sensitive
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Ensure that you are using the same level of security on all of your
wireless computers (None, 40/64 or 128 bit) and that all devices are
using the same keys, and the same order of keys where appropriate.
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Ensure that you have the Wireless computer enabled in the list of
allowed MAC addresses if you are using Wireless Connection control
on the Gateway.
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If you are having difficulty connecting or are operating at a low speed
try changing the antenna positions on the rear of the Gateway. For
more effective coverage you can try reorientating your antennae.
Place one antenna vertically and one horizontally to improve coverage.
Additionally consider moving the wireless computer closer to the
Gateway to confirm that the building structure or fittings are not
adversely affecting the connectivity. If this resolves the problem
consider relocating the Wireless computer or the Gateway, or trying a
different channel on the Gateway.
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Sources of interference: The 2.4Ghz ISM band is used for 802.11b.
This is generally a licence free band for low power applications, and
you may have other devices at your location that operate in this
frequency band. You should take care to ensure that there are no
devices like microwave ovens for example close to the Gateway or
wireless computers as this could affect receiver sensitivity and reduce
the performance of your network. If you are unsure try relocating both
the wireless computers and the Gateway to establish whether this
problem exists.
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Most wireless computer Adapters will scan the channels for the
wireless Gateway. If a wireless computer has not located the Gateway
then try initiating a search manually if the client software supports this
feature or manually set the channel on your wireless computer to
correspond to the Gateway channel number. Please refer to your
Wireless computer adapter documentation and vendor to do this.
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Speed of connection: The 802.11b standard will automatically choose
the best speed depending on the quality of your connection. As the
signal quality weakens then the speed falls back to a lower speed. The
speeds are 11Mbps, 5.5Mbps, 2Mbps and 1Mbps. In general the
closer you are to the Gateway the better the speed. If you are not
achieving the speed you had anticipated then try moving the antenna
on the Gateway or moving the Wireless computer closer to the
Gateway. In an ideal network the Gateway should be located in the