Modem Problems

Modem Info

Why can't I connect at the highest possible speed every time?
Reported initial connect speeds won't necessarily be dependable or even comparable from modem to modem or location to location. The reason is that V.34 modems can (and often do) speed shift up and down after the initial connection, and do so in a manner that is dependent on the particular connection as well as the particular equipment (including firmware versions) at each end. Some modems connect at a more conservative speed and then quickly upshift as conditions allow; other modems connect at a more aggressive speed only to quickly downshift (or worse, lose performance due to excessive errors). another problem is that software may report the receive speed for certain modems and the transmit speed for other modems, which can be substantially different. Unfortunately, it is not possible to monitor the actual modem speed during the connection for most modems. Regardless, the only thing that really counts is net throughput, which can be measured by many communications applications. If you consistently connect at 26400 or above, there may not be much that you can do to go faster -- it's simply not possible to achieve the highest V.34 speeds on many phone circuits. (This is not false modem advertising -- 28800 modems are designed to wring as much speed out of the actual real-world connection as possible, and 28800 or higher speed is only possible on a near-perfect connection.)
How can I improve my connect speeds?
There are several ways in which you can improve your chances of obtaining a higher connect speed, however most problems are associated with line quality.

The first is to make sure that you are using the proper Initialization String. Please click on this link to find the correct string for your modem. You may also wish to consult the user manual that came with your modem. Initialization String Info

Try plugging your modem into a different phone jack in your house or office.

Make sure there are no power cords near your phone line.

We recommend against using power strips or surge protectors with phone jacks in them. This can cause interference on the phone line.

Make sure that you have Error Correction and Flow Control enabled in your modem software. In Windows95 you can find these options by: Clicking the right mouse button on your "Perigee" icon in your Dial-Up Networking window, select "Properties" from the menu, your Perigee properties window will come up. Click on the "Configure" button, the "Connection Tab", the "Advanced" button. You will then see this window. Some of the options may be "greyed out" in your particular window. Not all modems support these features.

When I dial in I get dropped after a short time

Attach a telephone to the modem's phone line and make sure there is no noise or static on the line.

Make sure your call waiting is disabled. Any incoming calls will knock your modem offline while you are connected to Perigee. You can do this by adding *70,, before the phone number in your modem software. If you have Windows95 open your "Connect To" window and click on the "Dialing Properties" button. Check "This location has call waiting:" Select "*70," from the pull down menu.

Sometimes if you have the Port Speed set too fast on your computer overrun and framing errors can cause your modem to drop the connection. For 14.4 modems set your port speed to 19,200 and for 28.8 + modems set your port speed to 57,600.

Disconnections may be caused by momentary drops of DTR (Data Terminal Ready). By default, most modems respond to a drop of DTR by hanging up. With US Robotics and other modems, add S25=200 to your Modem String. This sets the duration, in hundredths of a second, that DTR must be dropped so that the modem doesn't interpret a random glitch as a DTR loss.
A similar possibility to the one above is that your modem could not distinguish between a line hit, or other disturbances that momentarily break the connection, from a true disconnect by the remote modem. Add S10=100 to the Modem String to set the duration, in tenths of a second, that the modem waits after loss of carrier before hanging up.

Initialization String Information
Initialization strings are commands that your computer uses to initialize or prepare your modem for use. If you do not have the proper initialization string set up on your computer you may not be utilizing the full capacity of your modem. This can also cause your modem to behave unpredictibly and drop the connection. Please follow some of the links below to find the proper string for your modem. Also make sure that you check your modem documentation first. It should list the proper init string for your modem.
Other Modem Information and Resources
Return to Perigee's home page | Suggestions