Jawaharlal Nehru Technological University Hyderabad B.Tech III PRINCIPLES OF COMPUTER COMMUNICATIONS AND NETWORKS Previous Question Paper (January/February - 2021 - R16)

Computer communication refers to the process of transferring data, information, or signals between two or more computing devices over a transmission medium. It involves the exchange of digital data using established protocols to ensure reliable and accurate delivery.

The role of networking in this process is fundamental:

• Resource Sharing: Networking allows multiple users to access shared hardware (like printers) and software applications, improving efficiency.
• Connectivity and Communication: It provides the physical and logical infrastructure to connect geographically dispersed devices, enabling email, instant messaging, and collaborative tools.
• Reliability and Redundancy: Networks provide alternative paths for data transmission, ensuring that communication continues even if one link fails.
• Scalability: Networking allows for the seamless addition of new devices and services to an existing infrastructure without disrupting overall operations.

The telephone system historically functioned as a circuit-switched network designed for analog voice transmission. It relies on a local loop (the connection between the subscriber and the central office), trunks (high-capacity lines between switching centers), and switching offices that establish a dedicated physical path for the duration of a call.

Data communications, by contrast, focus on the exchange of digital information between computers. Key concepts include:

• Data Representation: Information is converted into binary digits (0s and 1s) for processing and transmission.
• Transmission Modes: Data can be sent in simplex (one-way), half-duplex (two-way but not simultaneously), or full-duplex (simultaneous two-way) modes.
• Switching Techniques: While traditional telephony used circuit switching, modern data communications primarily utilize packet switching, where data is broken into smaller packets that travel independently across the network and are reassembled at the destination.
• Protocols: A set of rules, such as TCP/IP, that governs how data is formatted, addressed, and routed to ensure successful communication across diverse hardware environments.