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Modems & Connections
General Modem Troubleshooting
Here are some frequent problems that crop up that aren't specifically dependent
on the brand of modem being used. To those around the
world who use this resource, please be aware some of this troubleshooting
information is specific to Australia.
Buying a modem
Most of the time this rule will apply: "you get what you pay for".
There are good and bad modems and the performance will vary between them. Every
couple of months you will find a modem review in one of the Computer Magazines.
They are reliable tests that compare the performance of the common modems. Ask
your Internet Service Provider what they recommend. iiNet can provide you with
modems, that we find reliable and least troublesome when connecting to our
rotaries.
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Installing a modem
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. Please note that the connect speed between your modem and your computer
needs to be at least double the speed you want your modem to run at. 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 a site of the modem
manufacturer, it should be included in your manual. If it is not use a search
engine to find it.
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Protecting your modem
Your modem is one of the most delicate parts of your computer. Any electrical
surge can cause it to malfunction or not work at all. It is especially
susceptible to lightning. To fully protect your modem you need a special surge
protector. It protects the phone line as well as your modem power supply and
power supply for your computer. Visit iiNet Karrinyup Shop or a local computer
store to purchase one. Otherwise you will need to make sure that both power and
phone line are unplugged from the modem during a storm and when you are not
using it.
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Modem Drop-outs
Modem drop-outs are the most common problem associated with modem usage. The
modem disconnects without anyone, such as you or us initiating it or any other
obvious reasons. In actual fact there can be a lot of reasons for the drop-outs.
From noise on the line to some settings on your computer. Below you will find
some tips that can help reduce the problem and hopefully fix it :)
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Your modem hangs up every 5 to 20 minutes
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 its recall memory by drawing electrical current from
the phone line every 5 to 20 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 Telstra on 132200 (residential)
or 132000 (business).
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Your modem disconnects 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 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. If
Telstra resets their exchange the call waiting might be enabled automatically.
Please check for call waiting from time to time or if you have problems with
drop-outs.
Telephone double adaptors and very long extension cables can cause drop-outs.
Phone cables come in different qualities. If you are getting poor performance
from the modem and a lot of drop-outs, good quality phone cable is worth
investing in. If possible, try plugging the modem directly into the phone line
with no other devices attached anywhere in the house. Try it, it might make a
difference.
If you have a digital mobile phone, telephony between such a phone and a GSM
cellular base station can cause severe data transmission loss that can terminate
a modem 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 alarms communication cycle.
Actually, anything electric can cause interference with your modem. Check
what is turned on that is in close proximity of the phone line/modem. Things you
might want to watch out for are TV's, radios, microwave, fridge (especially when
it cycles on and off), washing machine going in to a spin cycle,
air-conditioning cycles etc. Do you get a better connection when those things
are off or on another power circuit? Try a surge protector. It protects the
phone line as well as your modem power supply and power supply for your
computer. Visit iiNet Karrinyup Shop or a local computer store to purchase one.
Other things that can create problems with modem drop-outs are poor
waterproofing on the phone lines. Especially if the problem becomes more
apparent when it is raining. Loose or old line wiring can also create noise on
the line and disconnect you from the Internet. That copper wire, which runs
around your house, down the street and to your local exchange can vary in
quality. If it is in a poor state, nothing else you do will make any difference.
Telstra's telephone Exchange and the distance to it can make a difference in
your connection performance. Some exchanges might have some good lines and some
bad lines so it is a lottery whether you get a good one. Each call you make may
be different.
Some of the above things will cause a noisy line. Call Telstra faults and get
them to check it (keeping in mind they only certify their lines to 2400 baud
which is much slower than an average modem today) Please note that Telstra will
only test line for voice quality and a very low data quality. Your modem is much
faster than that.
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You cannot get your modem running at its full speed
If you have a pre Pentium 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. To operate at 115200 bps you need a very good serial port. Try
TI- 16750. This information applies to IBM compatible PCs.
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You are dialing STD and cannot make a successful
connection
If you are experiencing problems with STD Pips interfering with data
transmission, phone Telstra to see if you can have them surpressed. Make sure
you are dialing the correct STD code before the telephone number. And always
keep in mind the STD charges.
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Modem cannot recognise the dial-tone
There are different dial tones available in the network. If your modem cannot
recognise the dial-tone make sure that the phone line is plugged into the
correct modem socket (usually: "Line"). Test the line to make sure
that there is a dial-tone by plugging a telephone into the same socket. Try to
make a call from it. If you have Telstra MessageBank you will hear a different
beeping dial-tone. Your modem will not recognise it as a dial-tone and you will
not be able to dial out.
You can change settings on your computer to ignore dial-tone and dial
regardless. In Windows95/98 untick the option "wait for dial tone before
dialing" in your modem properties. In Macintosh tick "Ignore the dial
tone" in your dialler or modem properties. You can also try adding x3 to
your modem initialisation string.
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You cannot use your PABX or Commander system to connect
Telstra does not recommend such systems be used for modem transmissions and
instead recommend that you install a specific data line outside of your phone
system for data communications. You can try dialling the line out number like
"0" or "9" before the phone number in your dialup settings.
That might help you connect, but please note that your connection will not be as
good as through a dedicated line.
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As soon as you start PPP/SLIP, everything stops
Check that you have hardware flow control, and a modem cable that supports this.
In Windows95/98 you can go to Control Panel, then Modems, choose Properties
under the modem you are using. Click on Connection tab then the Advanced button
and choose Use Flow Control: Hardware(RTS/CTS) In a Macintosh check your modem
properties in the ppp software you are using to connect.
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Your modem connection shows some huge amount like 57600 or
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.
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You are using a 56K modem: after a while connection stops
for a few moments, or hangs up 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 you 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/V90 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 56k flex modems try:
Forcing 44kbps: +ms=56,1,1200,44000
Forcing 42kbps: +ms=56,1,1200,42000
Forcing 40kbps: +ms=56,1,1200,40000
For 56k V90 modems try:
Forcing 44kbps: +ms=12,1,1200,44000
Forcing 42kbps: +ms=12,1,1200,42667
Forcing 38kbps: +ms=12,1,1200,38000
If your modem has problems accepting the above strings, try:
Forcing 44kbps: +ms=v90,1,1200,44000
Forcing 42kbps: +ms=v90,1,1200,42667
Forcing 38kbps: +ms=v90,1,1200,38000
And so forth, down to:
Forcing 33.6kbps: +ms=11,1,1200,33600
If your modem has problems accepting the above string, try:
Forcing 33.6kbps: +ms=v34,1,1200,33600
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If the strings above do not work with your modem, please refer to your
modem's manual.
To add an initialisation string on Windows95/98 go to Control Panel and
Modems, choose your modem and go to Properties. Click on Connection tab then
Advanced button. Extra settings is where you need to type the string.
On Macs, only freePPP dialler will allow you to change the initialisation
string. In the OTppp software, to include an initialisation string, you need to
generate a modem script. In Open Transport PPP software you should make sure you
are using a script supplied with your modem.
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