Nobody likes to see their Internet connection suddenly disconnect, especially right when they're trying to work. This document explains the various reasons, and offers suggestions for minimizing or eliminating, disconnection problems. Please note that this document covers disconnections that occur -after- you're connected to the service. If you are getting disconnected immediately after logging in, please see our Immediate Disconnection guide for more information about that particular problem.

When using an analog modem to access on-line services, there will almost invariably be an occasional disconnection. If this is a chronic problem for you, this document will help you find out what's causing the disconnections, and what you can do about fixing it.

One of the most common reasons for disconnection problems is line noise. When there is extended static or noise on a phone lines, or the signal becomes very weak, the two modems exchanging data can't "understand" each other. Most modems will pause when there is noise on the line and wait to recover the connection, but occasionally this is not possible, and the modems will disconnect from each other.

"Dropped connections can occur when there is a sharp decrease in line quality during a call. [28.8] modems will switch to rates as low as 4800 bps to compensate for these changes. If the loss of quality is extremely severe, they will drop the connection." -- USRobotics/3Com

There are often severe changes in line conditions during and after inclement weather. Moisture in the ground caused by storms, flooding or snowfall will cause noise on the line and make connections less reliable. Noise can be introduced in your home as well. If someone picks up an extension on the line that the modem using, your modem will not be able to communicate, and might disconnect. Similarly, poor in-house wiring, appliances that generate radio interference, or radio interference from local radio stations will cause disconnections. If you can hear noise, static or voices on your line when you make a call, chances are your connections to us will be unreliable. Also, other phone equipment on your line can cause problems of this sort. Older fax machines or cordless phones can cause interference that can affect your connection. You may wish to disconnect all of the phone equipment that is on the same extension your modem is on, and try plugging your modem into a different wall jack to see if your problem is indeed in-house.

There are many other conditions that might affect line quality as well. If you have tried all of our suggestions in this document and still experience disconnect problems, you may want to contact your telephone company's repair department. They may be able to fix severe problems with a noisy line. However, they will typically give a line a clean bill of health even if the line has problems that would keep your modem from connecting at speeds higher than 9600bps -- on a standard phone line, most phone companies only guarantee this low-speed connection.

For maximum line quality, CoreComm uses what are known as channelized T1 lines on most of our connections. These digital lines are similar to ISDN lines, and not only allow us to offer 56k service, but are also not as susceptible to the types of noise and signal problems that are common with standard analog lines.

The type of modem that you use can have a large bearing on the frequency of disconnections. The amount of money you spend on a modem determines, to a high degree, the stability of your connection. Not all modems are made equal, and the first place that modem manufacturers typically cut back is in the modem's error correction features. The following types of modems are, in our experience, the type of modems which are most prone to disconnections:

• Modems using the Rockwell RPI or RPI+ chipset. The most common modems of this sort are the Zoom 14.4 PC and the USRobotics Sportster SI (note that this is only true of the SI model). Check your modem's manual to see if your modem uses the RPI chipset.
• Original Gateway Telepath modems from the early 90's (this is not true of the later Telepath II models)
• Software modems, such as the LT WinModem, HSP modems, and Rockwell HCF modems.

If you have one of the above modems, we strongly recommend upgrading. The 3com/USRobotics Courier line of modems offer the most reliability in this matter, although the lower-cost Sportsters are typically fine (with the exception of the SI, as above). We have also found that "no-name" 33.6 modems based on the Rockwell chipset are more prone to line problems than others.

Another factor regarding your modem that can influence disconnections is if your modem has its error correction features disabled. Most modems will pause when noise on the line is encountered, but if those same modems have error correction turned off they may simply disconnect immediately. If you are using Windows95/98, you can check to see if your modem has error correction enabled by going into My Computer -> Dial-up Networking, right-click on the CoreComm icon and select Properties -> Configure -> Connection -> Advanced, and checking the "Use error control" option. If you are using another operating system, check your modem's guidebook or your modem's manufacturer for details on making sure error correction is enabled.

Disconnections can also occur if your modem's hardware handshaking features are not enabled. If your disconnections are occurring at times where you are actively receiving information (such as during a file download), you may want to check to see if this is enabled. On most Non-56k modems that are -not- manufactured by USRobotics, you may want to add the string &K3 to your software's initialization string to force this feature. With USRobotics modems, the default initialization string will enable this feature. If you are using Windows95/98, you can add &K3 to your init string by going into My Computer -> Dial-up Networking, right-click on the CoreComm icon and select Properties -> Configure -> Connection -> Advanced, and type it in the "Extra Settings" field. Note: If you add that to your init string and end up getting "No response from the modem" error messages, simply remove what you added and restart your computer.

Newer modems use flash-ROM firmware to control the modem, and is upgradeable by software. If you have such a modem (most recent USRobotics/3com, Supra and 56k modems have upgradable firmware), check on your modem manufacturer's web site or support department to see if an upgrade is available for your modem. The revision of your modem's firmware can have a major effect on the reliability of your modem.

Another common reason for lost connections is call waiting. The call waiting "beep" on the line is interpreted by modems as noise on the line, and can eventually cause a disconnection. In most areas, you can turn off call waiting by adding *70, before the phone number (check with your local phone company about the code to temporarily turn off call waiting in your area if you are not sure that "*70," is the correct code).

Inactivity can also cause disconnections. CoreComm has a 30 minute inactivity timeout, meaning that if you do not send any data over your Internet connection for 30 minutes, your connection will be dropped. When you type a message in your mail program (ex: Netscape or Eudora), or sit and read a web site, you're not actually sending any information out over the Internet until you actually send a message out, receive a new message, or load a new web page. If you want to stay connected, but will be composing a long message, be sure to check your mail or load a web page at regular intervals (every 10 minutes or so) in order to stay online. Most mail programs have a "Check mail every X minutes" to do this automatically - a feature that you may wish to enable.

Your Internet Dialer software will also drop connections due to inactivity, unrelated to CoreComm's inactivity timeout. If you're getting a message on your screen indicating that you're inactive, or your connection is dropping after a few minutes of transferring a file, chances are you have this feature enabled. In Windows95/98, you can disable it by going into My Computer -> Dial-up Networking, right-click on CoreComm, select Properties -> Configure -> Connection, and unchecking the "Disconnect if call is idle..." option. On the Macintosh, go into the FreePPP Setup icon in your Control Panels, and deselect the "Disconnect if idle for..." option in the General tab. If you are using PPP or Remote Access on a Macintosh, go to Apple Menu -> Control Panel -> PPP or Remote Access -> Options. In options, go to the connection tab. There you will see a check box for "disconnect if idle for X minutes." Either uncheck it or set it to a more appropriate amount of time. If you are using a different operating system, and you are uncertain as to how to change this setting in your software, you can send E-Mail to support@core.com with the name of the dialing software that you're using, as well as the operating system.

Disconnections may also be caused by a violation of your accounts limitations. As described in our System Policies, we only allow one dial-up connection at a time per account. So if you have two separate machines dialed up on two separate phone lines using the same login name, once our system verifies that you're online from more than one phone line, one of the connections will be dropped (typically, the most recent connection will be dropped within three minutes).

We may also disconnect customers if there is an extremely extended connection that we believe to be held by artificial means and is not being actively used (for example, if you accidentally left your computer online and it's set to check your mail every 10 minutes). This only applies to those holding connections for an extreme amount of time, so this is the case for only a very small number of disconnections, and does not affect the vast majority of our customers.