COMPUTER SOLUTIONS
Arvin Meyer has over 25 years of experience in fabricating wood, metal and plastic. He serves as a consultant and a technical writer to several companies. He is available for consulting on fabrication at the rate of $75 per hour. You may contact him at P.O. Box 125, Free Union, VA 22940, E-mail onsitesolution@mindspring.com. The design of a company's network involves more than just choosing an operating system. Considerations include topology, which software is appropriate, and which hardware gives performance. Important considerations include price, reliability, speed, number of users, type of applications running, and existing hardware. Existing Hardware: Before deciding almost anything else, take an inventory of all existing hardware, including copiers and fax machines. The functionality of copiers and fax machines can be duplicated somewhat by scanners and fax software. If you need high speed copying, a dedicated copier is required, otherwise a scanner can duplicate that functionality, and provide input of non-computer generated documents for fax software. Some computers may not be functional with the latest software, but will perform adequately as dedicated servers for printers and scanners. To run today's business applications software, I'd suggest workstations having at least a Pentium processor at 166MHz speed, with 64 Mb of RAM, and at least a 2Gb hard drive. Servers, depending upon the operating system and purpose, can be less than that. For instance, a 486DX66 is sufficient for most print servers. Type of Applications: If your users are using the network to log in and share files, and their primary applications are word processors and spreadsheets, your server needs are rather light. If each of your users prints from their own local printer, the server will not be required to feed a network printer. If there is only one bookkeeper, the accounting system can be run from a local machine. Normally a variety of application data and hardware is shared: databases, accounting systems, printers, etc. In this case, one should consider additional special purpose servers, one for the network printer(s), and one for the database, to reduce the load on the primary servers. If your operations are critical to business, a backup server should be employed. Number of Users: On a Windows NT network, it is recommended to use one server for each 2000 users (this assumes there will be other servers for specific purposes). Imagine that many users logging in at 9:00 AM, and you will see why I personally feel that that value is optimistic. Similarly, if you only have 15 users, but are running a database, an accounting system, and several printers, in addition to serving and backing up files, specialized servers improve performance markedly. Speed: Your main server should have at least 128 Mb of RAM, especially if it is doing the duty of serving occasional printing and database chores. This is true no matter what Network Operating System you choose, but especially true of NT4.0 and Novell4.xx when you are using them to also connect to the internet, and serve e-mail. I would also suggest that the Processor speed be above 166MHz. A 400MHz or 450 MHz machine will do better, and allow for future growth. Hard drives should be a minimum of 9Gb SCSI for a single drive, or three to five 6Gb drives if using RAID technology. Small networks get along quite nicely with an 8 GB IDE drive. Reliability: The server is no place to stint on quality. I have had very good luck with custom made machines, made by a nearby concern. (Platinum Micro Electronics in Manassas, VA 703-368-4584). When designing larger systems, or systems for remote clients, I have also had very good luck with Dell servers. (800-999-3355). Choose a system with more capacity than you need (at least double). Either you'll grow into it, or technology changes will require that growth. Price: For smaller systems, I have gotten better than competitive pricing from Platinum Micro Electronics. For larger systems, Dell seems to have better prices than the other large systems manufacturers. Price should not be the major concern. If your system's designer is selling a specific brand, and he has to support it, then you should buy his brand. I chose not to sell equipment very early in my systems engineering career because I felt I could not be objective if I was making a profit on a specific brand. If you choose a consultant who also sells equipment, be wary of what he is selling. Make sure, it is a recognized brand with factory service, or that he has the ability to service your equipment. Some dealer/system designers also work through service providers such as General Electric to provide service and that often works out well for smaller operations. Topology: At least 95% of all new, and 85% of existing systems are Ethernet. Ethernet is preferred because it is generally faster, and less expensive. Wiring should be Category5 cable which works with Ethernet (10BaseT) or Fast Ethernet. If you have more than 20 users, or are using larger file server databases (Access, FoxPro, Paradox, etc.), I'd suggest using Fast Ethernet. Doing so will increase network performance by a factor of 10, with an overall cost increase of less than twice. For smaller networks 10BaseT is usually more than adequate.