Home » Computer Science » Networking
21. 

Packet Switch Stream (PSS) was introduced in
A. the US in 1961 (&) the UK in 1981
B. the UK in 1980
C. the US in 1961
D. None of the above
22. 

The physical layer of a network
A. defines the electrical characteristics of signals passed between the computer and communication devices
B. controls error detection and correction
C. constructs packets of data and sends them across the network
D. All of the above
E. None of the above
23. 

Which of the following allows devices on one network to communicate with devices on another network?
A. multiplexer
B. gateway
C. t-switch
D. modern
E. None of the above
24. 

An error detecting code is which code is the remainder resulting from dividing the bits to be checked by a predetermined binary number, is known as
A. Cyclic redundancy check
B. Checksum
C. Error detecting code
D. Error rate
E. None of the above
25. 

Bulletin board system
A. is a public access message system
B. is a modem capable of accepting commands
C. converts analog signals to digital signals
D. converts digital signals to analog signals
E. None of the above