Connecting your LAN to the Internet

We shall assume you have already connected all your machines together into a LAN. Now you need to determine what kind of connection to an ISP you want, and what kind of equipment you will need. This page describes various connection methods, and these two pages discuss equipment needs:

• Routers and Hubs
• Software Routers

To get onto the Internet, you need to follow these steps:

1. Determine what connection methods are available to you and affordable:
   • shared modem,
   • xDSL,
   • ISDN,
   • cable modem,
   • T1 or frame relay or something like that.
2. Decide whether or not you need a full time connection (versus dial on demand) and whether or not you need fixed IP addresses (versus assigned temporarily at login). See about IP.
   • You need a full time connection if you intend to operate a server that other people can connect to. It is very rare to find an ISP that will dial you up, or a user that will wait that long for a server connection to get established.
   • Otherwise, a permanent connection is a very nice convenience, but not necessary.
   • A set of fixed IP addresses are necessary if you intend to operate a server or if you need to be easily identified on the internet (coming through a corporate firewall, for example.)
3. Find an ISP that will support your area with your connection type and IP needs. Obviously, this step may alter the steps above.
4. Order services as necessary: another phone line, an ISDN line, a xDSL line, a cable modem... Your ISP may do this for you and will certainly assist you.
5. Get the necessary customer-end equipment: a ordinary analog modem, an ISDN or DSL "modem" or router.
6. Attach the customer-end equipment to your network and set it up as necessary.
7. Modify the TCP/IP settings on the machines on your network to utilize the new connection.

Connection Comparison

Type	Typical Cost	Performance	Comments
Shared Modem	Cheap	about 33KB	Consumes entire phone line while in use. Not recommended for simultaneous use by more than one person.
xDSL	$30/mo for line $20/mo for ISP	256KB up to 1.5 MB	Full time connection. Line can be used for voice simultaneously
ISDN	$50/mo for line $30/mo for ISP	64KB to 128KB	Dial-up connection. You get two voice lines, one of which can be used simultaneously with data.
Cable Modem	?? I Don't Know	up to 1.5 MB	Full time connection. Performance is shared with neighbors. Can get slow if several are on line at the same time.
T1	$1000/mo	1.5 MB	This is the type of line most companies use to connect to the net.

Other methods include Frame Relay (56KB permanent connection), T3 (several T1s), PRI or E1 (32 64Kbit channels), OC3 (optical fibre). None of these are really suitable for home users.

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