User's Manual

MDS 05-6302A01, Rev. B MDS Mercury 16E Technical Manual 57
5. Optimize RSSI (less negative indicates a stronger signal) by slowly
adjusting the direction of the antenna. Watch the RSSI for several
seconds after making each adjustment so that it accurately reflects
any change in the link signal strength.
6. Once RSSI is optimized, view the Packets Dropped and Receive Error
rates. They should be the same or lower than the previous (recorded)
readings.
If the RSSI peak results in an increase in the Wireless Packets Dropped
and Received Error, the antenna may be aimed at an undesired signal
source. Try a different antenna orientation.
End of procedure.
7.0 PERFORMANCE NOTES
The following is a list of points that are useful for understanding the per-
formance of the radio in your installation.
7.1 Wireless Bridge
The transceiver acts as a Layer 2 network bridge. If any radio in your
network is connected to a large LAN, such as may be found in a large
office complex, there may be undesired multicast/broadcast traffic over
the air. As a bridge, the radios transmit this type of frame.
The radio goes through a listening and learning period at start-up before
it will send any packets over either of its ports. This is about 10 seconds
after the CPU’s operating system has finished its boot cycle.
The bridge in the transceiver operates and makes decisions about packet
forwarding just like any other bridge. The bridge builds a list of source
MAC addresses that it has seen on each of its ports.
There are a few general rules that are followed when a packet is received
on any port:
• If the destination address is a multicast or broadcast address,
forward the packet to all ports.
• If the destination address is not known, forward the packet to
all ports.
• If the destination address is known, forward the packet to the
port that the destination is known to be on.
• Spanning Tree Protocol (STP) is used by the bridge to pre-
vent loops from being created when connecting bridges in
parallel. For example, connecting two remotes to the same
wired LAN could create a loop if STP was not used. Every