Frequent Modem Disconnect Problems

Getting dropped offline?

There are several causes of dropped connections.

Problem:
Everytime I someone tries to called me I get bumped offline. What is going on?
Solution:
Do you have Call Waiting? Chances are that you do. So what you need to do is open your shortcut to MIS or Midcoast.com. Now you in front of the telephone number that is there you will want to add the following: *70, . For example: If you are using the telephone number of 1-500-699-7200 it should look like this: *70,1-500-699-7200 or *70,15006997200. Now when someone tries to call you when your on the internet, they will get a busy signal instead of knocking you offline. Just remember you can revese this process anytime by removing the *70,.
Problem:

With modems the most common cause of disconnects is connecting at TOO FAST a speed, causing frequent modem retrains, which in turn cause frequent disconnects. Most telephone lines will not support the maximum speed of the modem. With V.34 modems the best you should expect is 24,400 and any time you get a higher speed connection expect more frequent disconnects. With V.90 56Kbps modems, the expectations are highly dependent upon how the telephone company has provisioned your service and expectations range from a low of V.34 speeds to around 48K. The local loop to the Telco is very high quality so the modems will be fooled into training to a speed that your local loop from your house to your Telco will not support for very long unless you are very close in cable feet to the Telco. Speed renegotiations is the most problematic code in modems and you can not rely on it to hold a connection, in many cases it will fail and you will be disconnected.

Solution:

Try dropping your connect speed by forcing a lower speed, if that stops the disconnect then line noise may be the problem.

Problem:

The second most common cause of disconnects is modem incompatibilities, again typically related to re-trains. Get the latest firmware revision for your modem. Don't assume because you bought your modem recently it has current firmware. The statement 'my modem has no problems with Joe's Internet Service' is not particularly meaningful. Every modem will be compatible with someone, but we have yet to see the modem that is compatible with everyone. Our systems have been very reliable with current versions of firmware on modems from Hayes, Zoom, Supra, Motorola and many others... the biggest headaches come from the very low cost units ( namely WinModems, better known as LoseModems ). As modems become faster they also become more complex. Some modems have a way to record the reason why a connection failed. Popular methods include the ATi2 or AT&V1 command ( these are modem specific, your modem may vary ).

Solution:

First, avoid WinModems like the plague. Second, try using an external version of another brand modem and see if the problems disappear.

Problem:

Another common cause of disconnects is line noise.

Solution:

Unplug EVERYTHING connected to your phone lines: caller ID boxes, extension telephones, cordless telephones, other modems, fax machines, etc. Also unplug your laser printer and microwave oven from the AC wall outlet. We have learned that many telephone line surge protectors or noise filters will seriously impair your phone line. The modem should be the ONLY thing connected to your phone lines. If the problem goes away, then you have something in your house causing you to disconnect. Do not route the phone line within three inches of any electrical cord or extension cord, or PC CPU cable, Printer cable, Monitor cable, any electrical appliance or power supply. Especially avoid laser printers, cordless telephones and uninterruptable power supplies ( UPS ). Inductance from electrical lines and radio transmitters wreaks havoc with phone lines.

Problem:

If the line noise is not being induced inside your house it may be induced in the cable somewhere between your house and your local telephone exchange central office. Your line may have a one or more of conditions the Telco calls bridge, ground loop, cross talk, or bad loading coil. Any of these conditions will cause random noise and unpredictable disconnects.

Solution:
For noisy lines, try increasing a setting that tells the modem how long to wait ( in tenths of a second ) before hanging up when it loses carrier detect. This guard time allows the modem to distinguish between a line hit, or other disturbance that momentarily breaks the connection, from a true disconnect by the remote modem. For example: S10=100 setting will make your modem wait 10 seconds to make sure the other modem is really gone before hanging up. If this seems to help, contact your phone company and request the line be checked for noise at the network demarcation block at your house. Do not let them just check the line from the central office end, ask to meet the repairman at your house and get him to report the results of his tests to you. If you encounter resistance from them because you have a modem, call back and tell them your fax machine is not working well with your phone line.
Sometimes defective cables and loose connections will cause disconnects. For external modems, if the serial cable is old, adapter pins bent, or cable cracked, replace it or try another one. Make sure your serial connections are TIGHT. Examine your telephone cable between the wall jack and the modem, or better still try replacing it. If portions of the telephone cable between the network interface and your wall jack have been stapled to the wall, examine the cable carefully. If possible try another jack, or the jack on the Telco network interface itself.
Problem:

You may have a hardware conflict. Frequently we have seen internal modem cards configured in conflict with another COM port which will seem to work OK for a few minutes of the connection and then just freeze up. Check to see that your motherboard com2 port does not conflict with your modem, see your modem documentation for instructions on detecting and correcting IRQ conflicts. Also, if you have an Ethernet Card in your PC and an internal modem, it is almost certainly causing some problems with high speed modem connections over 9600 baud.

Solution:

The only cure we have found is to remove the Ethernet card or use an external modem on an high speed serial port.

Problem:

We have a 15 minute idle timer, which means if you leave your computer logged in, but do nothing which exchanges data over the link, then your call will be disconnected after 15 minutes of idle time. An example might be reading mail, then without a logout begin using MS Word to prepare a document to respond to a mail message you received. Using your word processor on your computer will not cause any data to be transmitted, so 15 minutes later the call will be disconnected.

Solution ( for non-timeout related issues ):

Some PC's have built in idle timers of their own. Win98, for example, has a 20 minute idle timer which is NOT enabled by default but which may have been inadvertently enabled and set to 3 minutes! Although rare, your modem may be set up to automatically disconnect after a certain period of inactivity. You may be able to fix the carrier loss problem by adding these settings to your modem initialization string: S19=0 This disables the inactivity timeout on most modems. If you want your modem to timeout and hang-up after a certain amount of time, you can replace the 0 with the number of minutes you want it to timeout after ( up to 255 minutes ).

Call Waiting:

If you have call waiting, make sure you disable this feature before connecting to the Internet. Disable call waiting is usually an additional service you must purchase from your local phone company. Call your phone company if you are unsure how to disable this feature on you phone. To automatically disable call waiting before connecting to the Internet do the following:

Before clicking the Connect button when connecting to the Internet, click the Dial Properties button.

Select This location has call waiting... and enter the code to disable call waiting.

Click OK.

Generally, you should hold a connection for as long as you wish.... there will ALWAYS be an occasional disconnect, we are after all dealing with phone lines which may be 20 years old or more, pushed to the very limits of their capacity when using the latest generation of modems. But you should not get repeated disconnects. If you do, something is wrong and you should methodically follow the steps above.