Data Communication and Computer Networks - Data Communication
66. Which of the following decides the role (sender or receiver) of a device on a network ?
- Option : C
- Explanation : Line discipline co-ordinate the link system. It determines which device can send and when it can send. Line discipline decides the role of a device on a network.
67. For stop-and-wait flow control, for n data packets sent, how many acknowledgments are needed ?
- Option : A
- Explanation : For stop-and-wait flow control for n data packets sent, in acknowledgements are needed.
69. In a crossbar with 1000 crosspoints, how many statistically are in use at any time ?
- Option : B
- Explanation : A crossbar switch connects n inputs to m outputs in a grid, using electronic micro switches at each cross point, totally n x m cross points are required for crossbar switch. In general 25 percent of the cross points are used at a given time. The rest are idle so, totally 1000 cross points, so 25% = 250 crosspoint points are in use.
70. Which of the following is a time - division switch?
- Option : D
- Explanation : In time division switch, slots are divided by time switching accomplished using time division multiplexing (TDM) and another device called time slot interchange (TSI).
