This article is from the Amiga Networking FAQ, by Richard Norman with numerous contributions by others.
ISP the Cheaper WAN:
ISP -- Internet Service Provider
WAN -- Wide Area Network
With this kind of connection all you have at your end is your Amiga, a modem, and a phone line. The ISP has all the network equipment at their site. You merely pay to use it.
Over this connection they provide SLIP and PPP which require some networking knowledge on the user's part but not as much as managing a LAN. SLIP and PPP offer a full set of internet services, but at a lower speed. Generally you are limited to what speeds the local telco can provide. The fastest is currently ISDN but that can be expensive and has limited availability. So most ISP's will also offer standard analog modem connections of 14.4K or higher. For those on a budget and who aren't afraid of command line mode you can usually get a shell account from ISP pretty cheap. They may even let you use TIA or a similar utility at no extra charge. Shop around.
Since these are normal phone lines and used on a part time dial up basis, this is nothing more than a fancy BBS, and thus the rates are lower. If you want a full time connection or ISDN speeds most ISPs can accommodate you...for a fee.
The other big difference between an ISP and a WAN provider is that most ISP's do not own any phone lines. Most ISP's rent them from WAN's and recoup the costs by selling dial up access. This has lead to a new cottage industry and it pays to shop around for service.
So how do you find an ISP? It is kind of ironic. If you have internet access, it is easy to find internet access. But if you don't have internet access, check the local papers, local BBS systems, user groups, etc. Once online you can usually keep abreast of what ISP's are available via a service called Yahoo which can be accessed via Mosaic at http://www.yahoo.com. Once connected look under the regional section. It goes down to the city level and if your city is listed chances are real good there will be a list of ISP's for your city.
Got deep pockets and want full time connectivity? go to the Full blown WAN section.
 
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