Progressive Hospital is split over two sites: Remuera and City Centre and is run by the City Centre Health Board (CCHB). The sites are connected by a dedicated fiber link and are managed as one network. There are also 30 Community Clinics which access the Hospital’s network using Telecom’s Frame Relay service. CCHB has approximately 15000 users and 200 servers.
Local Area Network
1 Network setup within each site:
At each of the two CCHB sites, there are two Core Switches. These are Cisco Catalyst 6500 switches incorporating Route Switch Modules (RSMs) for Layer 3 switching. (Appendix A)
The core switches are high end components, offering scalable switching bandwidth up to 256 Gbps. They are chassis based and accept cards to support different media. CCHB use a number of different card types, including 1Gbps fiber, 100Mbps fiber, 10Mbps fiber, 100Mbps UTP.
At each site, the second core switch is cascaded off the first. Building Switches are then cascaded off the Core Switches. These Building Switches are a variety of Cisco Catalyst Switches, including models 4000, 4500, 5000 and 5500. (Appendix B)
Servers are Compaq Proliant, running Windows operating system, or Sun Servers running UNIX. The UNIX machines are used for specific applications, usually involving an Oracle database. Management and maintenance of the Sun Servers is outsourced to EDS (New Zealand office of an international IT consultancy).
Each site has a secure server room, which requires card and pin code for access. Inside the room, four rows of approximately 200 rack-mounted servers are positioned on top of a false floor where all cabling runs, protected by H2O sensors. These sensors detect minute water quantities. On the ceiling are smoke detectors, and three air conditioning units circulate and regulate the air. Building switch rooms and building hub rooms are also secured through keyed access.
Each hospital building houses a building switch, and from this, 12-port hubs are cascaded (as many as required to service the building). The ports on the hubs are connected with UTP cable to RJ45 connection sockets for each individual workstation, modality, printer, etc. There are over 4000 ports supported across the entire organisation.
Servers connect directly to the Core Switches (diagram 1) and are located at either Remuera or City Centre depending on where most users of the particular server are based.
The servers are connected to the switches using 1Gbps fiber or 100Mbps UTP. The clients connect to the hubs using 100Mbps or 10Mbps.
The organisation uses TCP/IP exclusively for its LAN. Ethernet and Gigabit Ethernet are the Layer 2 protocols in use to support this.
Diagram1: Logical Network Diagram Remuera / City Centre.
2 Wireless LAN:
A small section of the City Centre site has been configured for a Wireless LAN, with Access Points positioned throughout the defined area. The size of the WLAN area is limited by the number of Access Points available for use. The WLAN has a number of limitations and specific issues, including the need for UPS devices, potential for interference with hospital equipment, increased security issues regarding network access and virus introduction, and the overall additional costs of supporting a wireless LAN.
Incorporation of the Route Switch Module in the Cisco switches means that the switches can provide both Layer 2 (switching) and Layer 3 (routing) functionality.
The Core Switches act as the routers for the site, handling traffic flows within and between the sites. When...