Computer Networks

A LAN covers a small geographic area like a single building or campus. WAN spans large distances, MAN covers a city-sized area, and WLAN is wireless LAN. The single-building scope defines a LAN.

In ring topology, all hosts are connected in a circular arrangement where each node connects to exactly two neighbors. Data flows around the ring through the common path. Cellular uses cells, star has a central node, and mesh connects everything directly.

Star topology has a central hub or switch through which all communication passes. Each node connects only to the central node, not to each other. This centralizes control and simplifies management.

Cellular topology broadcasts data over radio waves, making it inherently vulnerable to interception, eavesdropping, and unauthorized access since the medium is shared and publicly accessible. Linear bus, star, and ring topologies typically use wired connections which are physically more secure and harder to intercept without direct access.

Mesh topology provides multiple redundant paths between nodes, so if any link or node fails, traffic can route through alternative paths, making it ideal for uninterrupted communications. Ring topology has single points of failure between nodes. Star topology depends on the central switch. Hierarchical topology has single points of failure at each level.

A switch operates like a multiport bridge because it learns MAC addresses and forwards frames only to the specific port where the destination device is connected, unlike a hub which broadcasts to all ports. Switches operate at Layer 2 and provide dedicated bandwidth to each port.

A switch provides concentrated connectivity by connecting multiple devices while making transmission efficient through MAC address learning and selective forwarding. Unlike hubs that broadcast to all ports, switches send data only to the destination port, reducing collisions and improving performance.

Fourth Generation (4G) mobile networks natively support IPv6 to accommodate the vast number of mobile devices requiring unique IP addresses. IPv4 addresses are exhausted and cannot scale to meet 4G device density, while IPv5 was an experimental real-time stream protocol that was never deployed commercially.

At 10 Mbps with 20% overhead, effective bandwidth is 8 Mbps. Transferring 1 GB (approximately 8000 Mb) takes 8000/8 = 1000 seconds, or about 16.7 minutes. Option C (15 minutes) is the closest approximation among the choices.

Network bandwidth fundamentally measures throughput - the amount of data transmitted per unit of time across the network. Response time measures latency, number in the system is a queuing metric, and utilization measures capacity usage. Bandwidth is specifically about data transfer capacity.

A standard SCSI-1 or SCSI-2 adapter supports 7 devices, with the adapter occupying ID 7, leaving IDs 0-6 for devices. Wide SCSI and later versions support more, but typical SCSI adapter in this context refers to classic 8-bit SCSI. Answer 2 is too low, 8 doesn't account for the controller, and 2+7 is incorrect.

BlackBerry Router is the service component that establishes and maintains connections between the BlackBerry Enterprise Server and the wireless network infrastructure. It routes data packets to and from the carrier network.

The BlackBerry Router is responsible for connecting to the wireless network (the BlackBerry Infrastructure) via port 3101. The Dispatcher manages encryption/compression, the Messaging Agent handles mail queues, and the Controller monitors server services.

The Channel Subsystem in mainframe systems (like IBM z/Architecture) controls the direct transfer of data between the Control Unit (and attached I/O devices) and Central Storage. Other options describe transfers internal to control units or printers, rather than channel-controlled main storage access.

Infrastructure monitoring should be placed as close to the targets as possible to minimize network latency, reduce bandwidth usage, and improve accuracy of measurements. Monitoring across the internet introduces unnecessary complexity and potential data loss.