TREND EDS-205 - Manual (Page 9)

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Switching, Filtering, and Forwarding
Each time a packet arrives at one of the switched ports, a decision is
made to either filter or forward the packet. Packets with source and
destination addresses belonging to the same port segment will be
filtered, constraining those packets to one port, and relieving the rest of
the network from the need to process them. A packet with destination
address on another port segment will be forwarded to the appropriate
port, and will not be sent to the other ports where it is not needed.
Packets that are used in maintaining the operation of the network (such
as the occasional multi-cast packet) are forwarded to all ports.
MOXA EtherDevice Switch operates in the store-and-forward switching
mode, which eliminates bad packets and enables peak performance to
be achieved when there is heavy traffic on the network.
Switching and Address Learning
MOXA EtherDevice Switch has an address table that can hold up to 1K
node addresses, which makes it suitable for use with large networks.
The address tables are self-learning, so that as nodes are added or
removed, or moved from one segment to another, MOXA EtherDevice
Switch automatically keeps up with new node locations. An address-
aging algorithm causes the least-used addresses to be deleted in favor
of newer, more frequently used addresses. To reset the address buffer,
power down the unit and then power it back up.
Auto-Negotiation and Speed Sensing
All of MOXA EtherDevice Switch’s RJ45 Ethernet ports independently
support auto-negotiation for speeds in the 10BaseT and 100BaseTX
modes, with operation according to the IEEE 802.3u standard. This
means that some nodes could be operating at 10 Mbps, while at the
same time, other nodes are operating at 100 Mbps.
Auto-negotiation takes place when an RJ45 cable connection is made,
and then each time a LINK is enabled. MOXA EtherDevice Switch
advertises its capability for using either 10 Mbps or 100 Mbps
transmission speeds, with the device at the other end of the cable
expected to similarly advertise. Depending on what type of device is
connected, this will result in agreement to operate at a speed of either
10 Mbps or 100 Mbps.
If a MOXA EtherDevice Switch RJ45 Ethernet port is connected to a
non-negotiating device, it will default to 10 Mbps speed and half-duplex
mode, as required by the IEEE 802.3u standard.