Troubleshooting Connection Problems

by Jim Lewis, ISP Administrator


I receive e-mail from time to time from people asking various questions about problems they are having connecting to the Internet or being disconnected.  First of all let me assure you that we are not disconnecting you based on a time out period or other reasons.  We may have rarely disconnected someone due to equipment maintenance requiring resetting or switching equipment.  Secondly I can assure you that we have many customers that are not having these problems, can connect to our modems flawlessly time after time and stay connected for long periods of time.   That being said, let us examine the problems associated with modems and telephone lines.  From my experience I have found that most connection problems are from three different causes.  1.  Telephone line quality.  2.  Software based modems and 3.  Incompatibilities between modem manufaturers. 

Their is not much that can be done about the quality of your phone line as long as your voice conversations are of good quality.   The phone company is selling voice grade phone lines which is equavalent to around a 9600 baud modem connection.  The best approach is to get the most speed out of the phone line you got without having connection or disconnection problems.  To trouble shoot phone line problems I recommend trying a different phone line.  This is the main reason we have people bring their computers to our shop for diagnosis, so that we can try their modems out on a known good phone line. 

Software based modems unfortunately are the most common type of modem used today.  We do not normally use or sell these type of modems if it can be avoided.  Software modems are cheaper ($10 to $20) and this is why they are used in most computers.  The difference between a software based and hardware based modem is that a software based modem uses your computer processor to run programs or drivers in the background that perform the modem function.  This means that if you do not have a fast enough computer, or your computer is busy with other processes, it may lose sync and disconnect.  Hardware based modems on the other hand, are self contained devices that require very little use of your computer's processor.  They buffer data and pass it to your computer as it asks for it.  Most PCI modems and Winmodems are software based.  The first approach to solving problems with software based or even hardware based modems is to make sure that you have the latest drivers or software for you modem.

Modem incompatibilities is another less common connection problem.  Some manufacturer's modems just don't communicate well with others.  If you have a hardware based modem about the only thing that you can do is change to a different modem.  If you have a software based modem the first step is to get the latest drivers or software.  This will solve many connection problems.   Especially with modems manufactured before or right after the v.90 standard came out.  Most modem manufacturers revised their software several times during 1999 to solve various connection and incompatibility problems.

Determining the type of modem you have.

The brand and model of modem you have can usually be determined by looking at the modem settings in the control panel.  To do this:

Click on the Start Menu, Click on Settings and then Click on Control Panel.  On this screen find the Modems modems.jpg (1770 bytes)icon and double click it.  You will see a screen like the one below.

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On this screen you should normally see only one modem listed.  If is says some type of PCI or Winmodem then you should probably look for the most recent modem drivers.  These drivers can usually be downloaded from the Internet.  First look on the web site for the manufacturer of the PC that you own or the Modem manufacurer's web site.  Many modems are made from generic chip sets and it might not be evident who the actual manufacturer is.  Other sites to look are:


Advanced modem settings.

As mentioned previously I suggest setting you modem to work at the highest possible speed without disconnect problems.  This will probably require SLOWING your connection speed down.  During the v.90 modem connection process they negotiate the highest speed possible.  A few seconds or minutes later, as conditions change, the modems may loose sync and disconnect.   Finding a slower speed may provide a more reliable connection.  I have found that the throughput on a slightly slower connection is often faster due to less error correction and better data compression.  This is also a reason why after disconnecting and reconnecting you can stay connected.  The modems very likely have negotiated a slower speed.   Setting the modem connection speed can only be done in the Advanced section of the modem configuration under Dial up networking.  I can show you how to get there, but unfortunately the codes to set your modem speed vary from manufacurer to manufacturer as well as different chip sets.  First let us look at how to get there.

Double click on My Computer. Double click on the Dial up Networking folder.  You should see an icon there for the Computer Wares Internet connection.  With your right mouse button click on it once, this will bring up a menu, then left click on Properties.

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On the next screen click on the Configure button at the bottom.

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On the Configuration screen click on the Connection tab and then the Advanced button.

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On the Advanced setting screen first make sure that under Use error control the Required to connect is checked.  It is not by default.  You always want to connect with error control.  This has been know to fix some connection problems.

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In the Extra settings box you will notice the setup command:


This is the default setup for some (mostly ISA bus hardware based) Rockwell/Conexant chipset modems.  This is more than likely not the setup command you would use for your modem.  As an example if I wanted to force my modem to connect at a slower speed I might use a setup string like:


This would force a connection of no faster than 38000 baud which might be a better connection for me.  The trick is to find the proper setup command for your modem and try different speeds.   Once you find out what manufacture, model or chipset you have, then usually with a little research on the Internet you can find the setup commands.  In the past these commands were in the manual that came with your modem, but I haven't seen that for a while now. 

If you use a custom modem command and see a message like this:

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Then the setting you have entered are incorrect.   Also make sure after you enter a modem command that you click on all the OK buttons until you get completely out of the Dial up networking setup.