26. In OSI network architecture, the dialogue control and token management are responsibilities of

A. session layer
B. network layer
C. transport layer
D. data link layer
E. None of the above

27. Which of the following transmission systems provides the highest data rate to an individual device

A. Computer bus
B. Telephone lines
C. Voice band modem
D. leased lines
E. None of the above

28. Which of the following connectivity devices is used to extend a network on a purely mechanical basis?

A. Gateway
B. Switch
C. Router
D. Active hub

29. The IEEE 802 project of the 1980s involved further defining the lower two layers of the OSI model. A number of standards were agreed upon during that time. Which of the following is the standard for Ethernet?

A. 802.2
B. 802.3
C. 802.4
D. 802.5
E. 802.6

30. Which of the following digits are known as the terminal number of the Network User Address (NUA)?

A. 5-7
B. 1-4
C. 8-12
D. 13-14
E. None of the above