User's Manual

19
4. SWITCH OPERATION
4.1 Address Table
The Industrial Gigabit Ethernet Switch is implemented with an address
table. This address table is composed of many entries. Each entry is
used to store the address information of some nodes in the network,
including MAC address, port no, etc. This information comes from the
learning process of Industrial Gigabit Ethernet Switch.
4.2 Learning
When one packet comes in from any port, the Industrial Gigabit
Ethernet Switch will record the source address and port number, and
the other related information in address table. This information will be
used to decide either forwarding or ltering for future packets.
4.3 Forwarding & Filtering
When one packet comes from some ports of the Industrial Gigabit
Ethernet Switch, it will also check the destination address besides the
source address learning. The Industrial Gigabit Ethernet Switch will
look up the address table for the destination address. If not found,
this packet will be forwarded to all the other ports except the port
which this packet comes in. And these ports will transmit this packet
to the network it connected. If found, and the destination address is
located at different ports from this packet comes in, the Industrial
Gigabit Ethernet Switch will forward this packet to the port where
this destination address is located according to the information from
address table. But, if the destination address is located at the same
port with this packet comes in, then this packet will be ltered, thereby
increasing the network throughput and availability.