Networking

The main purpose of this project was to change the network architecture in such a way as to allow lab computers easier network access without being bound by lengthy network wiring. The lab computers are often moved around from project to project and easy network access was becoming a problem. After a detailed analysis of the current setup, it was determined that installing a wireless network in addition to the existing landline network would provide the best solution. The following describes the final configuration (see diagram on page 4).

Internet access is provided by a DSL modem connected to a router. The router in turn has two connections into it. One is a wireless Ethernet access point, which provides access to the network for all wireless computers, mainly from the lab. Two is an Ethernet switch which interfaces the remaining landline Ethernet computers. A print server is connected to the switch to allow network printing access.

Configuration of the router is accomplished via a web browser and logging into a specific local I.P. address on the router. The built in EPROM has software running on it which allows easy configuration of the functions. These functions include configuring the DHCP server, security settings, firewalls, access restrictions, etc. Configuration the wireless access point is also done via a similar interface; a USB cable us used to connect to the access point firmware and configure the SSID on the network as well as the WEP key for secure wireless communications.

The operating systems present on the various computers include Microsoft Windows 98, NT, 2000 and XP Professional. These provide a friendly user interface to the operators and, because they are from the same vendor, they interoperate efficiently. Because of their age, Windows 98 and NT are in the process of being phased out in favor of Windows XP Professional.

Typical data flow when transferring a file from the lab to a desktop computer for analysis would involve the data from the lab being sent wirelessly to the access point. From the access point, the data is transferred to the router, which in turn forwards the file to the appropriate computer on the network. If the destination computer is physically wired to the network, the data must pass through a multi-port switch before it reaches the destination computer. Each computer on the network has a unique I.P. address assigned to it by the router and this is how it is identified. When a printing