Case 1: A local hospital asks you to help improve its networks fault tolerance. The hospitals network carries critical patient care data in real time from both a mainframe host and several servers to workstations in operating rooms, doctors offices, the billing office, teaching labs, and remote clinics across the region. Of course, all of the data transferred is highly confidential and must not be lost or accessed by unauthorized personnel. Specifically, the network is configured as follows:

Six hundred workstations are connected to five shared servers that run Solaris. Fifty of these workstations serve as training computers in medical school classrooms. Two hundred workstations are located in doctors offices and are used to view and update patient records, submit accounting information, and so on. Twenty workstations are used in operating rooms to perform imaging and for accessing data in real time. The remaining workstations are used by administrative staff.

The clients are connected in a fully switched, star-wired bus network using Ethernet 1000Base-T technology.

An Internet gateway supports e-mail, online medical searches, and VPN communications with four remote clinics. The Internet connection is a T3 link to a local ISP.

A firewall prevents unauthorized access from the T3 connection into the hospitals network. The hospitals IT director asked you to identify the critical points of failure in her network and to suggest how she might eliminate them.

On a sheet of paper, draw a logical diagram of the network and identify the single points of failure, and then recommend which points of failure should be addressed to increase availability and how to achieve this goal.

(I want simple and straight forward answer as well as the diagram)