Mac OS X: Troubleshooting a dial-up (PPP) Internet connection

Mac OS X includes all the applications you need to access and use the Internet
right away. But what if your modem doesn't connect to the Internet or
frequently disconnects? Follow the easy steps below and you'll be back on the
Internet in no time.

Check phone outlet and cables, call waiting, and line quality

Make sure your phone outlet or "jack" works by connecting a telephone to it. If
it works, check the connection between the outlet and your computer.
Disconnect and reconnect the cable to be sure the it is firmly inserted. If you
are using an external modem, check the connection to your computer and its
power cord. Be sure cables are not cut, chewed, or otherwise damaged. If you
experience frequent or random disconnection, consider these possible causes:
Disconnect if idle for __ minutes enabled?

You may have set your computer to automatically disconnect from the
Internet after a period of inactivity. Check your PPP Options:
1. Open System Preferences.
2. Click Network.
3. From the Show menu, choose Internal Modem.
4. Click the PPP tab, then click PPP Options.
Be sure this is not your issue before spending time troubleshooting your
phone line. Similarly, your Internet service provider may automatically
disconnect you when you are idle. Ask your Internet service provider
what its idle disconnection policy is.

Call Waiting

If you have call waiting, your Internet connection may be interrupted by
an incoming call. Check your phone book or with your phone company
for help turning off call waiting on a per-call basis. In North America,
you usually just add "*70" to the dial-up number. Enter this code as a
prefix followed by two commas when typing your ISP's dial-up phone
number in Network preferences. For example, if your dial-up phone
number is 555-1111, enter "*70,,5551111" as your dial-up phone
number. The commas create a pause between tones, allowing the code
prefix to be acknowledged before dialing.

Phone off the hook
See if others in your home or office are trying to use the same line.

Environmental interference

It's possible that your phone line receives interference from a strong
electrical field, or an electric or radio appliance. Try a phone jack in
another area or remove potential sources of interference, if possible.

Phone line quality

Analog phone lines ("POTS," or plain old telephone service) are
generally maintained for voice quality. Your modem may reveal quality
issues with your phone line that are not considered when evaluating for
voice quality, and that are not perceptible to the human ear. If frequent
disconnects cannot be isolated to another cause, you may need to
investigate phone line quality by contacting your telephone company. If
you cannot resolve an issue with phone line quality, consider other
alternatives that may be available in your area, including cable, DSL,
ISDN, satellite service, and so forth.

For an expanded discussion of this subject matter, se
e "Troubleshooting Phone
Line Issues That Affect Modem Conn

Don't use the Ethernet port!

Your computer's Ethernet and modem ports look alike, but the Ethernet port is
wider. On many Macintosh computers, it's possible to plug a standard RJ-11
phone cable into the Ethernet port, though this has been prevented on some
models. Be sure to connect your phone cable to the modem port. Notice the
similarities and differences in these two ports, which have identifying icons:

Check connection settings

Check four things in Network preferences: that the modem is your primary
network interface, your dial-up account information, your TCP/IP settings, and
your modem settings. Follow these steps:

1. From the Apple menu, choose System Preferences.
2. From the View menu, choose Network.
3. Choose Active Network Ports from the Show pop-up menu
("Advanced" from the " Configure" pop-up menu prior to Mac OS X
4. Be sure that the checkbox for "Internal Modem" (or another modem) is
5. Drag Internal Modem to the top of the Port Configurations list to make it
the preferred, or primary, network interface.
6. Choose Internal Modem from the Show pop-up menu.
7. Click the PPP tab.
8. Check the Account Name and Telephone Number fields to be sure you
have correctly entered the information your ISP gave you.
9. If you choose to save your password, retype it to be sure it is correct.
10. Click the TCP/IP tab. Follow your ISP's instructions for setting up this
pane. For more information, see "Mac OS X: How to connect to the
Internet with PPP (dial-up access)".
11. Click the Modem tab. In the Modem pop-up menu, be sure you have
selected a modem script that matches your modem.
12. If your telephone exchange is limited to either Tone or Pulse, be sure
that the radio button selected next to "Dialing:" matches your
13. If you subscribe to voicemail service that lets you know when you have
a message with a "beeping" dial tone, deselect the checkbox for "Wait
for dial tone before dialing."
14. If you have made any changes, click Apply Now.

Get the latest software

Under certain circumstances, your modem may need a software update in
order to work. If you have an Apple built -in modem, be sure you have the
latest update for the version of Mac OS X that you are using, and that you
have installed any applicable modem updates for your computer model.
Search Apple Downloads using the word "modem" and the model name of your
computer. If you have a third-party modem, check the manufacturer's website
for possible modem script, driver, or firmware updates.