PLANET WGSD-10020HP - Manual (Page 333)

User’s Manual of WGSD-10020 Series
5. SWITCH OPERATION
5.1 Address Table
The Managed Switch is implemented with an address table. This address table composed of many entries. Each entry is used
to store the address information of some node in network, including MAC address, port no, etc. This information comes from the
learning process of Managed Switch.
5.2 Learning
When one packet comes in from any port, the Managed Switch will record the source address, port no, and the other related
information in address table. This information will be used to decide either forwarding or filtering for future packets.
5.3 Forwarding & Filtering
When one packet comes from some port of the Managed Switch, it will also check the destination address besides the source
address learning. The Managed 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 a different port from this packet comes in, the Managed
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 filtered,
thereby increasing the network throughput and availability.
5.4 Store-and-Forward
Store-and-Forward is one type of packet-forwarding techniques. A Store-and-Forward Managed Switch stores the incoming
frame in an internal buffer and does the complete error checking before transmission. Therefore, no errorneous packets will
occur, so it is the best choice when a network needs efficiency and stability.
The Managed Switch scans the destination address from the packet-header, searches the routing table provided for the
incoming port and forwards the packet, only if required. The fast forwarding makes the switch attractive for connecting servers
directly to the network, thereby increasing throughput and availability. However, the switch is most commonly used to segment
existence hubs, which nearly always improves the overall performance. An Ethernet Switching can be easily configured in any
Ethernet network environment to significantly boost bandwidth using conventional cabling and adapters.
Owing to the learning function of the Managed Switch, the source address and corresponding port number of each incoming
and outgoing packet are stored in a routing table. This information is subsequently used to filter packets whose destination
address is on the same segment as the source address. This confines network traffic to its respective domain and reduce the
overall load on the network.
The Managed Switch performs "Store and Fforward" and thus, no errorneous packets will occur. More reliably, it reduces
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