FAQ - Modem Problems

Here are some frequent problems that crop up that aren't specifically dependant on the brand of modem being used.

My modem disconnects every 5 to 15 minutes for no reason
This is a common problem when you have a fax machine or a telephone plugged into the same phone line as the modem. In particular, the Telecom T200 Touchphone recharges its batteries for it's recall memory by drawing electrical current from the phone line every 5 to 15 minutes. This is enough to interrupt high speed data transmission using a modem. To solve this you can either unplug the phone when you use your modem, buy a new phone, or if you are renting your phone from Telstra (as most people do), they will probably replace it at no charge for a Touchphone 200R which solves this problem.

Telstra recommends that a 'mode 3' socket is installed for use with the modem, if any other equipment is in parallel with it. This will isolate the other equipment on the line whilst the modem is in use. To have a Telstra Technician install this socket, please contact 132200 (residential) or 132000 (business).

My modem disconnects before my minimum two hours
You may have call waiting turned on. If a call comes through with call waiting enabled, your modem will usually drop the connection. To turn it off you need to dial #43# before connecting, and to re-enable it, dial *43#. Remember that Telstra have recently enabled call waiting on almost all home phone lines. Also, telephone double adaptors and very long extension cables have been known to cause problems, so if possible, try plugging the modem directly into the phone line with no other devices attached anywhere in the house.

Failing that, you may have a noisy line. Call Telstra faults and get them to check it (keeping in mind they only certify their lines to 2400 baud)

If you have a digital mobile phone, telephony between such a phone and a GSM cellular base station can cause severe data transmission loss which can terminate a call.

If you have a burglar alarm which automatically dials and transmits data, this will affect your line quality. Ensure your modem communications are not carried out during it's communications cycle.

I can not get my modem running at its full speed
If you have a older computer, check the UART. An 8250 UART is considered unreliable above 9600 baud, and it is recommended that the UART is upgraded to the 16550 UART. Only 486 and early Pentium computers have the 8250 UART, all recent computers have the 16550 UART as standard.

Modem doesn't find a dial-tone
There are different dial tones available in the network. If your modem is not recognising dial tone, check with a telephone that dial tone is available from the socket. If dial tone is available, your initialisation string will need to be changed (usually by adding an X3 to the end)

I am using a 56K modem, and when I connect at high speed after a while it stops for a few moments, or disconnects completely
56K modems push the phone line to the limit, and need to "retrain" (that means change speed) regularly to keep up with the line conditions. It takes a few seconds to do this retraining, and these are the pauses the may experience.

Sometimes, when the retraining occurs, it can't successfully negotiate a new speed and will hang up.

As this problem becomes more pronounced the faster your modem runs, if you are experiencing difficulties it may be wise to "lock" your modem at a certain speed. First try intermediate speeds such as 44kbps, 40kbps etc. Failing all else, turn off K56Flex in your modem all together and connect with 33.6kbps.

Check your modem manual for instructions on how to do this, or try something like this in your init string (For Netcomms):

Forcing 42kbps: +ms=56,1,300,42000
Forcing 40kbps: +ms=56,1,300,40000

and so forth, down to
Forcing 33.6kbps: +ms=11,1,300,33600