Physical Topology

Correct Answer: Mesh

The 'Mesh' topology offers the best fault tolerance and redundancy. In a Mesh network topology, each network node is connected to every other node, providing multiple paths for data to travel. This means if one connection goes down, the network can continue operating using alternative paths. The 'Star', 'Ring' and 'Bus' topologies, in contrast, have single points of failure. In the 'Star' topology, if the central node fails, the whole network goes down. Similarly, in the 'Ring' topology, a single break in the ring can disrupt the entire network. The 'Bus' topology also has a single point of failure as all devices are connected to a single central cable.

Correct Answer: Bus

The answer is Bus. In a bus topology, all nodes (computers, servers, etc.) on the network are connected to a single cable called a 'bus'. Packet collisions are a common issue in bus topology because if two nodes send packets at the same time, they will collide on the cable. Star topology would not amplify packet collisions as each node has its individual connection to the network switch or hub and collisions at the switch are handled by the device itself. Similarly, in a ring topology, data communication is managed through a token system, thus minimizing the possibilities of collisions. Mesh topology, due to its connection redundancy and use of routing logic, plays a great role in reducing the chances of packet collisions. Hence, in the given scenario, the bus topology is most likely in use.

Correct Answer: Star

The Star topology would be the best fit for a small office with 20 devices. In a Star network, each device has a dedicated point-to-point link to a central network hub or switch. Because of this, it benefits from easy troubleshooting and configuration, since any problem with a particular link can be isolated without affecting other devices. This could not be achieved with the other topologies mentioned. In a Mesh topology, all devices are interconnected which increases complexity, making it not suitable for such a small office setting. With a Bus topology, all devices are connected to a single cable which could lead to congestion and makes it harder to isolate issues. Finally, in a Ring topology, while it's simple, a node failure can disrupt the entire network which could cause business disruption in an office setting.