16. Contention is
A. One or more conductors that serve as a common connection for a related group of devices
B. a continuous frequency capable of being modulated or impressed with a second signal
C. the condition when two or more stations attempt to use the same channel at the same time
D. a collection of interconnected functional units that provides a data communications service among stations attached to the network
E. None of the above
17. Avalanche photodiode receivers can detect hits of transmitted data by receiving
A. 100 photons
B. 200 photons
C. 300 photons
D. 400 photons
E. None of the above
18. Satellite-Switched Time-Division Multiple Access (SS/TDMA) is
A. the method of determining which device has access to the transmission medium at any time.
B. a medium access control technique for multiple access transmission media
C. a form of TDMA in which circuit switching is used to dynamically change the channel assignments
D. All of the above
E. None of the above
19. When you ping the loopback address, a packet is sent where?
A. On the network
B. Down through the layers of the IP architecture and then up the layers again
C. Across the wire
D. through the loopback dongle
E. None of the above
20. Which of the following TCP/IP protocol is used for transferring electronic mail messages from one machine to another?
A. FTP
B. SNMP
C. SMTP
D. RPC
E. None of the above