User's Manual

ViewSonic 3-in-1 Access Point 37
up on pin eight at the other end. They "cross-over" from one side to the
other.
CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance).
The principle medium access method employed by IEEE 802.11 WLANs. It
is a "listen before talk": method of minimizing (but not eliminating) collisions
caused by simultaneous transmission by multiple radios. IEEE 802.11 states
collision avoidance method rather than collision detection must be used,
because the standard employs half duplex radios-radios capable of
transmission or reception-but not both simultaneously. Unlike conventional
wired Ethernet nodes, a WLAN station cannot detect a collision while
transmitting. If a collision occurs, the transmitting station will not receive an
ACK knowledge packet from the intended receive station. For this reason,
ACK packets have a higher priority than all other network traffic. After
completion of a data transmission, the receive station will begin
transmission of the ACK packet before any other node can begin
transmitting a new data packet. All other stations must wait a longer pseudo
randomized period of time before transmitting. If an ACK packet is not
received, the transmitting station will wait for a subsequent opportunity to
retry transmission.
CSMA/CD (Carrier Sense Multiple Access/Collision Detection). A
method of managing traffic and reducing noise on an Ethernet network. A
network device transmits data after detecting that a channel is available.
However, if two devices transmit data simultaneously, the sending devices
detect a collision and retransmit after a random time delay.
DC power module. Modules that convert AC power to DC. Depending on
manufacturer and product, these modules can range from typical "wall wart"
transformers that plug into a wall socket and provide DC power via a tiny
plug to larger, enterprise-level Power Over Ethernet systems that inject DC
power into the Ethernet cables connecting access points.
DHCP (Dynamic Host Configuration Protocol). A utility that enables a
server to dynamically assign IP addresses from a predefined list and limit
their time of use so that they can be reassigned. Without DHCP, an IT
Manager would have to manually enter in all the IP addresses of all the
computers on the network. When DHCP is used, whenever a computer logs
onto the network, it automatically gets an IP address assigned to it.
Dial-up. A communication connection via the standard telephone network,
or Plain Old Telephone Service (POTS).