Cobalt Digital Inc COBALT Qube 3 User Manual page 280

Appendix G: Glossary
Carrier sense multiple access with collision detection (CSMA/CD)
A protocol that requires carrier sense and in which a transmitting data station
that detects another signal while transmitting stops sending, sends a jam
signal and then waits for a variable period of time before sending again.
Used in ethernet LAN technology.
CGI
See Common gateway interface (CGI).
Common gateway interface (CGI)
A set of rules that describe how a Web server communicates with another
application running on the same computer and how the application (called a
CGI program) communicates with the Web server. Any application can be a
CGI program if it handles input and output according to the CGI standard.
Collision
In an ethernet network, a collision is the result of two devices attempting to
transmit data at exactly the same time. The network detects the "collision" of
the two transmitted packets and discards them both. Collisions are a natural
occurrence on an ethernet network.
Ethernet technology uses carrier sense multiple access/collision detect
(CSMA/CD) to allow devices to take turns using the signal carrier line.
When a device wants to transmit, it checks the signal level of the line to
determine whether another device is already using it. If the line is already in
use, the device waits and tries again, perhaps in a few seconds. If the line is
not in use, the device transmits.
However, two devices can transmit at the same time in which case a collision
occurs and both devices detect it. Each device then waits a random amount
of time and retries until successful in getting the transmission sent.
CSMA/CD
See carrier sense multiple access with collision detection (CSMA/CD).
DHCP
See Dynamic Host Configuration Protocol (DHCP).
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