Network basics
What is a Network?
In its simplest form, a network consists of a group of connected computers sharing resources such as documents and printers. A term you'll often hear to describe computers connected in this way is "local-area network," or LAN.
Networks are popular because they can save a great deal of time and money. Imagine a five-person office in which all five computers are connected to each other and to a single printer. Only one computer is connected to a phone line.
Just a few ways in which this setup would be time- and cost-effective include the ability to:
- Buy fewer floppy/zip disks: Business plans, letters and other documents can be sent back and forth electron ically, removing most of the need for disks.
- Buy/service/depreciate fewer printers and other expensive peripherals: If everybody in the office uses one printer instead of five separate printers, the costs of buying and operating four printers completely disappears.
- Pay a smaller monthly telephone or ISDN bill: Since a single phone/ISDN line gives Internet access to everyone, monthly charges are saved on four other lines. You can save on both phone lines and the number of user accounts.
Servers and Clients
You may have heard networks described as "peer-to-peer" or as "client-server."
A peer-to-peer network is one in which all of the machines connected together have the same capabilities. A network put together with tools built into Microsoft 95/98 or NT 4 is a peer-to-peer network.
In client-server networks, one computer-called the server-is designated to serve the needs and carry out requests from the other computers, called clients. It's similar to being waited on in a restaurant: you're a client, and the person who brings the meal you requested is the server.
The distinction between peer-to-peer and client-server networks has blurred as desktop computers have gained power. It's become common for a network to have characteristics of both, and the distinction is more often made at the applications level than at the machine level. You can have one computer acting as a file server and another as a mail server on a network that is otherwise peer-to-peer.
WinProxy is server software. This means that, when it's installed on a computer, that computer becomes the network's proxy server. The other computers on the network are client computers.
The computer running the proxy server software-called the WinProxy computer or the server throughout this book-can also be a client computer. This may sound confusing but it really isn't. It simply means that the WinProxy computer fulfills its job as a proxy server, but other applications on that computer can be clients to the proxy server. The WinProxy computer doesn't need to dedicate itself solely to proxy tasks-you can keep using it for your regular computing.
NATS, Proxies and Firewalls
A proxy is simply someone/something who acts on behalf of someone/something else. Think of WinProxy as a trusted, computerized associate who acts for you on the Internet.
NAT stands for Network Address Translation. It's a simple, efficient technology used for connecting one Internet address to another.
Both NATs and Proxies provide methods to connect computers on private networks to the Internet at large, while making it appear to the Internet that all of the connections from that private network come from one computer.
A NAT provides an easy interface and is transparent to the application, but provides little opportunity for the user to modify or control the connection.
A Proxy provides much more control and makes possible a greater range of features to the user, but can only be used by proxy-supported applications. Most major Internet applications have such support, but many packages do not.
In real-world terms, a firewall is a fireproof wall used as a barrier to prevent the spread of fire. In computer parlance, a firewall acts as a barrier to Internet intruders. In other words, it protects networked computers (behind the firewall) from unwanted access by Internet computers (outside the firewall). At the same time, it allows networked computers to gain access to the Internet.
Acting as a proxy, the WinProxy computer gains access to the Internet on behalf of the other computers on your network. Then it acts as a firewall, preventing Internet intruders from gaining access to your computers and wreaking havoc with your data.
The WinProxy Network
WinProxy is a combination NAT/Proxy/firewall server designed to run on computers using Windows 95/98/NT/ 2000/Me/XP. The other computers on your network can run on any operating system capable of communicating with the TCP/IP protocol, including Mac and Unix/Linux systems. Every computer on the WinProxy network can access the Internet through the WinProxy computer and its single Internet connection. All network computers can attain simultaneous access while the users appear, to computers on the Internet, to be at the same computer address.
All computers on the network operate behind a protective and secure firewall. Although people inside the firewall can connect out, people on the outside cannot connect to computers behind the firewall. This provides security to the data on your network's computers.
Security is very important to those of us at Ositis Software. You'll notice throughout this guide that we offer many tips to enhance your network's security.
