Power Tools: Setting up a SLIP/PPP Connection

NetGuide, May 1, 1995

Domain Street, U.S.A. -- With a direct Internet connection, the P-P-Possibilities are endless

If you're ready to venture out beyond the safe haven of the commercial online services, then it's time to consider plugging yourself directly into the Internet. Direct Internet connections, such as SLIP and PPP, are popular because they allow you to use applications such as World-Wide Web browsers and sophisticated e-mail programs without having to learn any of the tricky Unix computer operating system. They also allow you to access a wealth of online content such as Internet Relay Chat and videoconferencing that the commercial services don't offer.

Setting up a direct Internet connection requires a lot of determination, a cursory understanding of the Internet's operating protocols and much tolerance for frustration. The folks who invented direct Internet connections did so long before Al Gore promoted the concept of an ''information superhighway.'' The original intended audience for dial-up Internet connections had the technical skills required to configure the software properly. Ironically, once a direct Internet connection is up and running, the Internet becomes easier to use. So there is a real incentive to clear this first hurdle and take the plunge.


To establish a dial-up direct Internet connection, your computer must learn to speak the language of the Internet, known as TCP/IP (Transmission Control Protocol/Internet Protocol). This universal language of data switching acts as the glue to bind the millions of computers that form the Internet. To connect into the net, your computer needs special software that links and translates between TCP/IP and your computer's operating system (whether it be DOS, OS/2, Windows or the Macintosh's System 7).

This service comes in two parts: a pipe that actually passes the bits back and forth between your PC and the Internet, and a TCP/IP translator that turns that data into intelligible information. The pipe comes in either PPP (Point- to-Point Protocol) or SLIP (Serial Line Internet Protocol) versions. Both perform the task of data transfer but differ in reliability. In most cases, both perform equally well, but in a few arcane situations PPP is less likely to crash. For this reason, opt for PPP over SLIP if you can.


For Macintosh users, Apple Computer Inc. provides a control panel or translator named MacTCP that provides the TCP/IP translation. For the pipe, you'll need a Mac SLIP or PPP program. Two popular choices are MacSLIP and MacPPP. These programs, when combined with MacTCP, create a direct Internet connection.

Of the many programs available for Windows, the most popular is called Winsock. Unlike the Macintosh, Winsock combines the TCP/IP translator and data pipe in one package. Picture a hierarchy: PPP or SLIP gets data from the Internet; the TCP/IP translator turns it into PC-friendly information; your system then passes that data to the appropriate application (such as an e-mail program or Web browser). The whole process gets reversed when you decide to send data like an e-mail message back out into the Internet.

The least expensive and easiest way to acquire this software is to purchase one of two books, both written by Adam Engst, that come with disks containing everything needed to get started. Published by Hayden Books, The Internet Starter Kit for Macintosh and The Internet Starter Kit for Windows each costs $29.95. These books boast instructions and troubleshooting solutions for just about any situation you might come across while setting up your direct IP connection. Engst provides excellent software for e-mail, newsgroup reading and file retrieval. He invites readers to download more Internet software for free from his Internet site.

Many other Internet books, such as The Internet Unleashed ($44.95, Sams Publishing) and Riding the Internet Highway ($24.95, New Riders Publishing), come equipped with all-in-one Internet software starter kits, such as the popular Chameleon for Windows.

This Internet connection software is also available as part of several commercial Internet starter kits, including Wentworth Worldwide Media's All-In-One Internet and Spry Inc.'s Internet In a Box. These packages, which can be purchased in any computer superstore, cost anywhere from $50 to $100 or more, depending upon the applications included. (See related article on the following page for more information about Internet kits and services).

Truly ambitious puzzle-solvers, the kind who like building computers from kits, can attempt to download the software instead of getting it with a book or kit. Of course, this requires online access in some form or another. A simple Internet terminal connection or even limited Internet access through one of the commercial online services will suffice. America Online and CompuServe offer several different shareware Internet software applications in their Internet forums. Windows users will find Winsock shareware at several Internet sites including ftp.tidbits.com in the /pub/slip/winsock directory. Mac users can download additional Internet tools from the same site in the /pub/tidbits/tisk directory. MacTCP is also available directly from Apple for $60.

Service Providers

For a direct IP connection to work, your computer must be connected to an Internet service provider. The service provider incurs the cost of a 24-hour, seven-day-a-week Internet presence, known as a ''node.'' This provider spends the thousands of dollars needed to maintain high-speed communications lines, workstations and so forth. It then, in the spirit of free enterprise, offers you access at whatever price the market will bear. Pricing in urban areas tends to be competitive. In metropolises like New York and Chicago, you should pay no more than $35 a month for unlimited, unrestricted direct IP access, or $20 a month plus $2 an hour. In return, the service provider must give you an e-mail account and access to Usenet news. Better providers may offer storage space on their computers for your files, the ability to create and make publicly available your own World-Wide Web home page and good support for properly configuring your direct IP software.

Finding the best provider in your area requires that you ask around. If you have access to e-mail, send a message to info-deli-server@pdial.com with ''Send PDIAL'' in the message body (do not include the quotation marks, but otherwise type in exactly as shown). You will get by e-mail a wonderful, up- to-date list of Internet service providers worldwide.


Once you have selected a service provider, you can set up your account. The most important piece of information you'll need from your Internet service provider is your Domain Naming System, or DNS. The DNS is a database on your service provider's home computer that acts as an address book for the Internet, making sense of the millions of computers connected. For example, when you download a file, the DNS understands where ftp.thatschool.edu actually is, and switches you over to it. The address of the DNS usually looks like dns.providername.com.

The two other important pieces of information: the addresses of your mail server (usually known as a POP account) and of your news server, the machines that perform electronic mail and Usenet newsgroup storing and forwarding for your provider. These addresses would typically appear as mailserver.providername.com and news.providername.com, respectively, with the names of your provider's mail and news server substituted appropriately. You will also need to know the gateway address or IP number for your Internet provider.

A final, and very important item, is your personal IP address (this differs from your e-mail address.) Since Direct IP turns your computer into a bona fide, albeit temporary, domain on the Internet, you are assigned a domain address for the duration of your connection (that way, other computers know where to find you). Question is, what is that address? There are two basic options. With a ''manual'' address, your Internet provider assigns you a fixed number that never changes. This will be a string of numbers like In your SLIP or PPP software, whether it be Winsock or a variant for Windows, or MacSLIP or MacPPP or a variant for the Macintosh, you go to the configuration section for the software and type in this number (where this configuration section is varies depending on the SLIP or PPP software you decide to use).

For many service providers, this method is falling out of favor. Imagine if a service provider has 4,000 users and 200 modems. That means it must issue 4,000 separate numbers, even though its peak capacity is limited to 200 simultaneous users. The solution? Issue the users a different number, culled from an open pool of numbers, each time they call in. Called ''server'' addressing, this obviates the need to know your personal IP address; the server picks one for you each time you call in. Most service providers fall into this category. A final kind of addressing, called ''dynamic,'' is designed for bridging Macintosh local area networks into the Internet. Home users should not be concerned with dynamic addressing but may see it listed as a choice in their software.

Next, you need to add other important information to whatever software you are using to make your IP connection (whether it be Winsock or Chameleon on the PC or MacSLIP or MacPPP on the Macintosh). You'll need to enter the service provider's phone number, a modem initialization string (varies depending on the modem), port speed (try setting it to 57.6 kilobits per second--even if your modem only goes to 14.4, you may get better transfer speeds that way) and flow control (this is for error-checking data; ''CTS only'' usually is best, but don't sweat this too much).

Finally, logging on requires a user ID and password. You can add this every time you sign onto your service provider or, if you prefer, develop a script to automate this process. Many Internet software kits such as Chameleon for Windows or IBM's Internet Connection for OS/2 come with prewritten scripts for the most popular nationwide Internet access providers. In that case, all you need to do is choose your provider from a list, click on an icon and your computer will automatically dial and sign onto your SLIP or PPP account.

Once your direct IP connection is made, you need to acquire the appropriate Internet software applications. Essential applications include an e-mail program, news reader, file transfer application for FTP and a Web browser. Optional applications you'll probably want are a Telnet program for logging onto other computers, such as library catalogs, and gopher, a file retrieval program that searches computers for the programs that interest you. With direct IP, you can even run a videoconferencing program called CU-SeeMe, where, with a $99 camera, you can speak with and see people all over the world. In the next few months we'll take a look at each of these applications and explain what to look for when shopping for them.

As technology advances, the need to fiddle with SLIP and PPP connections will fade away in favor of simple push-button Internet connections built directly into operating systems. In the meantime, armed with the information above, don't be afraid to experiment.

by David S. Bennahum