First I would begin by incorporating the star topology with an extended topology. I would do this because I can upgrade the network by replacing the problem components such as the 10mbs Ethernet hubs and the existing cables. I would replace the hub with a gigabit switch and add gigabit wireless router for the five computers to connect to the network. I would replace the 10 computer network interface cards with a 10/100/1000 Mbps NIC and replace the old cable with cat6 Ethernet cables and the five additional computer with wireless cards to negate the wiring problem. Finally, I would add a server for security and allow access for authorize users. I think all these components should help with the lag in the system when transferring large files and solve the bandwidth problems. And the five computers with seamlessly fit into the network without any additional cables.
Case Project 3-2
Based on our text I think a physical star has a lot of advantages and it would be better suited for this example. A peer to peer has too many disadvantages to work in this scenario. It is not centralized, there is a lack of security in this setup and only a small group of computer will be able to connect at a time with a peer to peer. With a server based network it will be easier to add and manage multiple computers, all file will be centralized and this way I can add 50 computers each to the five servers in compliance with what the client needs are based on the example. A switch is easiest to replace and in terms of what offer the best access it would be a network interface card.
Case Project 3-3
Since this is a large company I think their need will be better suited with server based setup. And based on the number of computer described in the scenario I will say they need a hundred and ten computers to meet their needs. a switched point-to-point topology or a logical or a switched logical topology using a physical star topology would be suited for this...