Intermec 6710 - Manual (Page 30)

SECTION 2
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Features and Functional Overview
2-6 6710 Access Point User’s Guide
Flooding Configurations
Standard LAN bridges flood frames on all ports when the
destination address is unknown. Additionally, many
network protocols use multicast addressing for connection
and status communications. A multicast frame is a special
type of frame destined for more than one physical address.
Standard bridges always flood multicast frames.
Most wireless media supported in the access point operate
at lower media speeds than Ethernet. Indiscriminate
flooding from a busy Ethernet backbone to a wireless
medium can consume a substantial portion of the available
wireless bandwidth. This reduces system performance even
though flooded frames are frequently not intended for
stations on a given wireless segment.
To allow performance tuning, the access point provides
separate flooding control options for both unicast (single
physical address) and multicast frames. Access points
serving as designated bridges connecting wired LAN
segments may be configured to use different flooding
settings than access points serving only wireless stations.
Two of the wireless media supported in the access point —
synthesized UHF (S-UHF) and 900 MHz — provide reliable
attach mechanisms, which guarantee that wireless stations
are always in the access point’s forwarding database.
Unicast flooding is never required for these stations.
The Wireless LAN Interoperability Forum (WLIF) 2.4 GHz
option also provides a reliable attach mechanism for
stations using the NORAND R Network Layer (NNL)
terminal emulation network protocol. Multicast flooding
levels are set for individual networks based on the needs of
wireless stations to receive multicast frames. For networks
with IP wireless stations only, the Proxy ARP Server
provides an option to enabling multicast flooding.