Mesh Topology

Correct Answer: Network congestion

In a mesh topology, every device is connected to every other device on the network. This provides a high level of redundancy, but it can also lead to network congestion, especially during peak usage times when many devices are trying to send and receive data simultaneously. The other options are less likely. Hardware failure would typically result in a complete loss of connectivity, not just slow performance. Collisions are less likely in a mesh network because each device has a direct connection to every other device. A single point of failure is not a likely cause because the mesh topology is specifically designed to avoid this problem - if one device fails, data can still be transmitted via the other connections.

Correct Answer: Wireless Mesh Network

The best option for an organization wanting to implement a wireless network in a building with steel infrastructure, which often causes signal interference, would be a 'Wireless Mesh Network'. This is because, in a wireless mesh network, each network node not only captures and disseminates its own data, but also serves as a relay for other nodes. In other words, it uses a network topology where each node relays data for the network. This ensures continuous connectivity even in the presence of interference as the data has multiple potential paths to reach its destination. The 'Full Mesh' and 'Partial Mesh' are types of network topologies, but they are not inherently wireless and would require additional hardware to ensure wireless connectivity. 'Star' is a type of network where each node connects to a central network hub or switch, this wouldn't be beneficial in an environment with steel infrastructure due to the potential for signal interference with the central hub or switch. Therefore, these are not the best options in this scenario.

Correct Answer: Partial Mesh

The best choice for a topology that doesn’t sacrifice too much fault tolerance yet reduces maintenance cost would be 'Partial Mesh'. Partial Mesh topology provides a balance between redundancy and cost-effectiveness. In a partial mesh topology, some devices are organized in a full mesh, while others are only connected to one or two in the network, reducing the cost of redundant links. Full Mesh topology, although it offers high fault tolerance, it's quite expensive and complex to set up and maintain. Star topology, while being cheaper and easier to set up, it does not offer as much fault tolerance as the mesh - if central node fails, the whole network is disrupted. Ring topology also offers less fault tolerance because a break in the ring can take down the whole network.