26. Most data communications involving telegraph lines use:

A. simplex lines
B. wideband channels
C. narrowband channels
D. dialed service
E. None of the above

27. You have a network ID of 134.57.0.0 with 8 subnets. You need to allow the largest possible number of host IDs per subnet. Which subnet mask should you assign?

A. 255.255.224.0
B. 255.255.240.0
C. 255.255.248.0
D. 255.255.252.0
E. 255.255.255.255

28. Modulation is the process of

A. sending a file from one computer to another computer
B. converting digital signals to analog signals
C. converting analog signals to digital signals
D. echoing every character that is received
E. None of the above

29. Which multiplexing technique shifts each signal to a different carrier frequency?

A. FDM
B. synchronous TDM
C. asynchronous TDM
D. All of the above

30. Which of the following protocol is connection-oriented?

A. IPX
B. UDP
C. NetBEUI
D. TCP