Many data communication networks have been established which provide a wealth of on-demand information services to people at home. What is the name of the system which provides an interactive, graphics-rich service that permits user to select what they want?

Protocols are

A. Agreements on how communication components and DTE

B. Logical communication channels used for transferri

C. Physical communication channels used for transferr

D. None of the above

The method of communication in which transmission takes place in both directions, but only one direction at a time is called

A. Simplex

B. Four wire circuit

C. Full Duplex

D. Half Duplex

Error detection at the data link level is achieved by

A. Bit Stuffing

B. Cyclic Redundancy Code

C. Hamming Code

D. Equalization

Which of the following is a wrong example of network layer?

A. Internet Protocol (IP) - ARPANET

B. X.25 Packet Level Protocol (PLP)-ISO

C. Source routing and domain naming-USENet

D. X.25 level 2-ISO