Hundreds of modems are available on the market, all with their own peculiarities and idiosyncrasies. Some modems can present a challenge for the user. You will find that in order for the modem to perform correctly both modem hardware and modem software - the driver - need to be setup and configured properly.

When you install a modem make sure you install it with the shipped, correct modem driver. How your modem is installed will affect its performance. You can follow instructions on the correct installation procedure from your modem manual.

Note that the connect speed between your modem and your computer needs to be at least double the speed at which you want your modem to run. Set the port speed in the modem properties to 115200. If you are running standard win95 modem driver, you will not be able to do that. You should download a new driver update for your modem from the Internet. Look for the web site of the modem manufacturer, it should be included in your manual. If it is not, use a search engine to find it.

If your modem disconnects you unexpectedly, you may have call waiting turned on. If a call comes through with call waiting enabled, your modem will usually drop the connection.
To disable call waiting on your modem

1. Click the Start button and choose Settings and then choose Control Panel.
2. In Control Panel, double click the Modem icon.
3. In Modems Properties, put a check in the box beside "To disable call waiting dial:" and type *70 in the white box on that line.

Many of today's modems can recover from significant line noise hits - including the call waiting tone that you may get if you have the call waiting feature on your line. If you have call waiting, in most areas, you are able to disable it prior to placing a call by dialling a code (usually *70) before dialling your ISP's number.
If a person tries to call you while you are on the net, they will get a busy signal. If you don't disable call waiting and your modem doesn't disconnect on the call waiting tone, the caller will hear your phone ringing and ringing and ringing. You might be able to get your modem to disconnect on call waiting tone by lowering the modems disconnect on loss of carrier register.

Consult your modem documentation for the register and values. The process is not a simple one and varies according to the modem used.

First, static electricity caused by radio signals, power lines, and other sources interfere with most 56K modem signals, forcing them to fall back to 42-50Kbps. Other devices on the phone line or devices the phone line runs through (like splitters) can slow down your connection speed. 56K modems also require a clean, straight through telephone connection to the telephone company's central office switching centre.
Phone company PBX switchboard systems and other phone equipment can alter the phone signal and force 56K modems to fall back in speed. Finally, the FCC doesn't allow 56K modems to use the full range of signals that phone company equipment can generate. They're concerned that it'll cause static interference to other phone lines. So no 56K modem in the United States ever connects at 56K. Most 56K modem users seem to connect at speeds of 44-48Kbps.

Second, you must look at how bandwidth or modem speed is measured. Much of the confusion in about bandwidth speed comes down to how we "count" file sizes and transmission rates. File sizes are measured in "K" for Kilobytes. A Kilobyte (abbreviated either K or KB) is comprised of one thousand bytes, a byte is comprised of eight bits,. Transmission rates are measured in the number of bits that we can send through a network within a given period of time. Now that we can send thousands of bits per second through a phone wire we measure transmission rates in kilobits per second, or thousand-bits per second. You may see this abbreviated kbps or Kbps.
Since there are eight bits per byte that means you are getting eight times less data pushed through the network than you might have thought.

In other words a 56k modem (more precisely a 56kbps modem) is moving only 7 Kilobytes of data every second (56,000 bits = 7,000 bytes). That means a 56Kbps modem can only move 7K of data per second.
Your modem connection shows some huge amount like 115200 - what's happening? Your modem has been setup to show the port speed, which can be changed in modem properties on your system. It is reporting the speed between your modem and your computer instead of the speed between your modem and the ISP. To show the actual connection speed add w2 to your initialisation string.

• Connection Error - no dial tone If your modem cannot recognise the dial tone, test the line to make sure that the phone line is working by plugging a telephone into the same socket and making a call. Make sure that the phone line is plugged into the correct jack on the modem (usually: "Line"). Unplug and plug the phone line in again to ensure you have a good connection. If the modem is external, make sure it is turned on.
  Verify that the "Wait for dial tone before dialling" option is enabled. To do this,
  1. Click Start, then Settings, and then Control Panel.
  2. Double-click Modems. Click your modem, and then click Properties.
  3. Click the Connection tab. Select the Wait for dial tone before dialling check box.
  4. Click OK, click Close, and then close the Control Panel.

  If you have voice mail you will hear a studder tone when you have new messages. Your modem will not recognise it as a dial tone and you will not be able to dial out. Make sure to check your voice mail right before going on-line or you can have the studder tone removed by ATMC.

  Adding commas (which causes pauses before dialling) in front of the number you are dialling can sometimes help. Open up the dial-up networking icon for your connection and add two or three commas in front of the phone number.

  If these steps do not adequately resolve the issue, the computer manufacturer, or the modem manufacturer may be able to provide further assistance. Also, consider replacing the phone cord itself or having the line or phone jack checked.

• Connection Error - modem is busy or not responding This error usually occurs when the modem settings are incorrect. Either the modem settings are in conflict with another device, the registry contains incorrect or damaged communications settings, or the modem is being controlled by another communications program.

You can also download a program to test a modem here. It has a 30 day evaluation period that is data dependant,