3Com PathBuilder S200 Series Owner's Manual page 53

Transparent Bridge Figure 27 shows how the Forwarder and the Hardware Accelerator process a frame.
Forwarder Example
A frame arrives at the
TB Forwarder.
YES
Is
the MAC
Source Address in the
forwarding
table?
YES
Is
the MAC
Destination Address in
the forwarding
table?
YES
TB Forwarder checks
if any filters are set.
Do
filters
match?
NO
TB Forwarder gives the
frame to the appropriate
handler as found in the
forwarding table.
Figure 27. How the Forwarder and Hardware Accelerator Process a
Frame
Forwarder
In addition, the Forwarder collects the following types of statistics:
Statistics
Bridging
T0008-16F
Drop
the frame.
YES
Do
NO
filters
match?
NO
TB Forwarder checks
if any filters are set.
Do
filters
match?
YES
YES
Drop
the frame.
Handler sends
the frame.
• Filtering
• LAN link
• WAN link
• Link error
Transparent Bridging for Ethernet LANs
Is
the inbound
NO
flag for a Unicast or
Multicast frame
set?
YES
Is
the MAC
Source Address on the
Permanent Station
Address
List?
NO
NO
Drop
the frame.
TB Forwarder gives the
frame to the handlers
that are in the
forwarding state.
NO
Learn the Source
Address.
YES
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