User`s guide
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Switch - Similar to a HUB, a switch is a multiple port Ethernet connection
device that allows for multiple Ethernet devices to communicate between
each other. Unlike a HUB, a switch has internal logic that determines
which port a specic MAC address is found on, and once it has
determined that, it only forwards trafc destined for that address to that
port. This allows for fewer collisions on the LAN by not re-transmitting
every packet on every port. Multiple simultaneous point-point
communications can pass through a switch at the same time, as long as
each end point is on a different port on the switch.
Like a HUB, a switch (in its primary mode) has no IP or MAC address of
it’s own. Also like a HUB, a switch uses HUB pin out on its connectors to
allow direct connections to NIC interfaces. Switches are more modern
devices than HUBS and are usually capable of 100 Mbit/sec (100 Base-
Tx) operation.
As a result of the requirement of IEEE Ethernet specs requiring
downward compatibility, all 100 Mbit interfaces must also support legacy
10 Mbit communications. This results in a requiring a switch to have
memory to store packets received at 100 Mbits for retransmission at 10
Mbits (Store and Forward).
T568A/B - The EIA/TIA structured wiring standards for
telecommunications wiring. A and B versions are electrically identical
and can not be distinguished with a wiring test. The color codes and
pair numbering is different, however, and care must be taken to use one
version within a network. A cable wired to A on one end and B on the
other results in a cross-over cable.
UPLINK - A special connector, or a mechanical switch, that changes the
pin out of one connector on a HUB or switch to NIC pin out. This allows
a straight-through cable to be used to connect one HUB (or switch) to
another while building a LAN.