IT Consultancy Introduction Computer Purchase Accounting Systems Local Area Networking Wide Area Networking ECommerce IT Protocols and Policies

Local Area Networks

Once you have acquired two or more computers, it is inevitable that you will eventually want to share files, printers, scanners and peripherals.  This is the reason the local area network has developed.  A local area network is so-called because the network joins two or more computers which are located within a local area. In a local area network this may be as much as several hundred metres but is typically far less. A wide-area network on the other hand uses long-haul technology such as that provided by telecomms companies to connect computers distributed beyond the limits of the local area network. Computers in a wide area network may be hundreds or even thousands of miles apart. 

 The R A Clement Associates network has evolved to the point where it now includes three hubs, two switches and three routers. Network performance is monitored to ensure that the network design and technology does not constrain the workflow required of the system as a whole. Where potential improvements are identified then these are considered using cost benefit analysis before being implemented. R A Clement Associates has been using a local area network since 1990. During this time the number of computers connected to the network has grown to the point where today almost every member of staff has a personal computer attached to the network. The network supports a range of printers (16 in all) for use by all staff members. The primary function of the network was and remains the use of IRIS incomplete records (accounts production) software. In addition it also supports standard office applications (Microsoft Word and Excel) and shared access to the Internet via a broadband connection. Internal and external email are provided by a dedicated email server, running Softtalk WorkgroupMail. Three other servers are also connected, one is dedicated to the IRIS applications for accounts production and tax return processing. 

A network has to be both easy to connect to by those with the right to do so and impossible to connect to by anyone else. The opposing demands of easy access for legitimate users and exclusion of unauthorised users provide the greatest challenge for network administrators.  The R A Clement Associates local area network is protected by several levels of security, ensuring that access is restricted to the users who are authorised to use and access the resources and information that they require and nothing else. All network users have a user name and password for access to the Novell network which provides the core services for file storage and sharing and printer sharing. If appropriate, users will also have administrative privileges on their computer allowing them to manage their own PC. Otherwise their access to their computer is restricted and they are prevented from accidental changes which they may otherwise make. 

Each workstation has a software firewall in place which is transparent to users of the local area network but which logs access to and from the rest of the network. This allows any attempt to circumvent the security mechanisms in place to be identified. In addition to the software firewall the workstations also run independent anti-virus scanning software which scans and monitors file access to prevent damage by virus programs. This software automatically updates itself to identify new or variant viruses should one infect the system.