Computer Networks

In a layered network architecture (like OSI or TCP/IP), each layer is designed to provide specific services to the layer immediately above it. This abstraction allows higher layers to function without needing to know the implementation details of the lower layers.

An interface is the point of interaction between two adjacent layers in a network model. It defines which primitive operations and services the lower layer makes available to the upper one.

A well-designed interface minimizes the amount of information that must be passed between layers. This follows the principle of information hiding and modularity, ensuring that layers remain independent and efficient.

Network architecture provides the framework for how different components interact through a structured set of layers and protocols. This design ensures that various hardware and software systems can communicate effectively. Computer architecture, by contrast, refers to the internal design of a single computer system.

Interfaces are local to a specific machine and define how adjacent layers interact within that system. Because different machines may use different hardware or operating systems, their internal interfaces do not need to be identical. As long as the peer-to-peer protocols used for communication are the same, the machines can successfully exchange data.

Full duplex communication allows for simultaneous two-way data transfer, much like a modern telephone call. This mode maximizes throughput by allowing both parties to send and receive at the same time. Simplex and half-duplex modes restrict this simultaneous capability.

Simplex communication is strictly unidirectional, meaning data flows only from the transmitter to the receiver. A common example is a television broadcast where the viewer cannot send data back to the station. Duplex modes are required for any form of two-way interaction.

Addressing is the mechanism used to uniquely identify the source and destination of a data packet within a network. Without a proper addressing scheme, routers and switches would have no way to determine where a packet should be delivered. Multiplexing and assembling are related to data handling but do not define the destination.

Half duplex communication allows data to be sent in both directions, but only one direction at a time. This is similar to using a walkie-talkie where users must take turns speaking. It differs from full duplex, which allows simultaneous two-way communication.

Multiplexing is the process of combining multiple data streams into a single signal over a shared communication medium. This allows a single high-capacity connection to be used for many independent conversations simultaneously, improving efficiency. Demultiplexing is the reverse process performed at the receiving end to separate the streams.

LAN stands for Local Area Network, WAN for Wide Area Network, MAN for Metropolitan Area Network, and CD for Compact Disk. Option B correctly matches all four pairs.

Videotex (spelled here as Video-Tax) was an early system designed to deliver interactive information services, including text and graphics, to a television screen via a telephone network.

 A device that connects to a network without the use of cables is called wireless.

BSC (Binary Synchronous Communications) is a character-oriented link protocol developed by IBM in the 1960s for synchronous data transmission. It was widely used for communication between mainframes and remote terminals.

Broadband networking uses a modulated carrier to transmit data signals over a medium, allowing for higher data rates compared to baseband networking.