Try plugging directly into your outside phone box. By disconnecting your inside wire and connecting directly to the outside phone box you can verify that the telephone company line is clear. As a last resort, try connecting with your computer at a friend's house who lives in your area to see if you get connected and stay connected. This will determine if your line quality is as good as your neighbor's. Or, visit your local computer store and get them to do a connect test at their location.
Older homes are especially prone to problems with wiring.
Any wiring from your phone box to the inside of your home or business is the customer's responsibility to maintain unless you have chosen the wire maintenance plan offered through your local telephone provider. We suggest getting old outside phone boxes replaced. CAT 5 shielded or unshielded cable to improve line noise reduction. In some cases we've seen connection rates double. Standard phone cable and systems were not designed for reliable data transmission.