Data Communication and Networks

RARP stands for Reverse Address Resolution Protocol. It finds the logical address for a machine that knows only its physical address.One or more unique logical (IP) address is assigned to host or router and this address is independent from the physical (hardware) address of the machine because it knows the physical address, but not its IP adress, so this is the correct answer.

Clock synchronization is used in the preamble of an Ethernet network. It provides synchronization and input timing to the frame to alert the receiving system.

NFS stands for Network File System. It allows a system to share directories and files with others over a network. By using NFS, users and programs can access files on remote systems almost as if they were local files.

Every device has a dedicated point to point link to every other device. Dedicated means that, the link carries traffic only between the two devices it connects. Therefore, mesh topology provides bidirectional links between each possible nodes.

Data link control is a bit oriented protocol for managing the flow of information in a data communication system.

Broadband LAN uses frequency division multiplexing on a coaxial cable to exchange information.

The X.25 protocol operate on all the three, i.e. physical, data link and network layers of OSI model.

When one device wants to send data to another device, a SEL frame is sent first. Before sending data, the primary device creates and transmits a select (SEL) frame, which includes the address of the secondary device. Select function is used, when primary device wants to send something to secondary device.

In manchester code, the bit duration is divided into the two halves. The voltage remains same at one level during first half and second half. It moves to the other level and the middle level to provide synchronization. It is like unipolar in which, the signal does not return zero at the middle of the bit and manchester is a combined feature of RZ and NRZ-L(polar). So, it is the correct option.

In half duplex mode, each station can transmit and receive data but not at the same time. When one device is sending the data, the other can only receive, and vice versa. Radio is the example of half duplex, where at a time one can talk and other can listen, and vice versa.

This is a class B host address. The range of first byte of class B is 128-191. The left most n bits(prefix) define the network and the rightmost 32-n bits define the host.

6B9B scheme is used to increase single-ended interface bandwidth and this also reduces active power consumption.

ANSI stands for American National Standard Institute which is a private, non-profit organization that creates standards for computer organisations.

Address resolution protocol is used to map an IP address into a hardware address because ARP is used to map a logical address or IP address into a physical address or hardware address. So, this is the correct answer.

All of the above are client-server programs.