| Issue |
Resolution |
| High
pitch/solid handshake tone produced by modem on dial in. |
Bad modem drivers
or phone line noise. Update
drivers (see Modems for a vendor list) and possilby have
phone line(s) checked by local telephone provider. |
| Staggered
Dial Tone. |
Modem issue.
Enter the initialization
string: S6=10 |
| Gets
disconnected/bumped off while online. |
Line
noise or driver issue.
1. User must update modem driver
(see Modems for a vendor list).
2. Have ISP/local telephone provider check for line noise.
3. Put in the initialization string: S10=100S25=200, lower the port speed, and
remove compression in your modem settings.
4. Remove all telephony devices and any splits in the line.
5. For more info check here.
|
| Error
629 |
Bad user id/password.
Remove script in dial-up networking and re-enter u#/password. |
| Error
645, 650, & 729 |
V.90 incompatability/driver
out of sync.
1. Disable
v.90 with init string, remove compression, and lower port=38.4kbps in modem
settings.
2. Update driver your modem driver (see Modems for a
vendor list). |
| My
ISP read me some History Call/Line diagnostic levels. What are acceptable line
levels? |
What each
reading means:
RxSpeed: The recieve speed in bps.
TxSpeed: The transmit speed in bps.
Modultn: The protocol used (v90, X2,...)
Retrn: # of retrains
ReNego: # of renegotiations.
ErrProto: Protocol errors.
FarEndEchoLvl: Less than RxLineLvl
RxLineLvl: -18dBm to -13dBm
SNR: -31dBm to -34dBm
TxErrs: Transmit errors.
RxErrs: Recieve errors.
Most customers should connect
with v.90 or X2 and should be reflected in the modulation area. Older modems will
however connect at v.34 if they are not 56k v.90 compatible. Slow connections
are caused by line noise or bad drivers. The TxSpeed will reflect the connection
speed while the RxSpeed will always be lower (that is normal). If a protocol is
at fault it will show up in ErrProto. Retrains and renegotiations are caused by
line noise or drive incompatibilities. The RxLineLvl should always be between
-18dBm to -13dBm. Any line under -21dBm is far too weak to carry a v.90 signal.
The far end echo should always be less than the RxLineLvl. The Signal to Noise
Ratio (SNR) should always be between -31dBm and -34dBm. Anything higher the -29dBm
is far too noisy to carry a v.90 signal. A signifigantly high number of transmit
or recieve errors could denote a driver problem (specifically either v.42bis,
which is compression) or error control problems (ECC). Driver updates, a dedicated
line (no splitters or telephony devices), and a clear line are a must.
|
| What
can cause line noise? |
A short, disruption,
or tone shift in the wiring or phone equipment. Make
sure the modem line is dedicated (no splitters, splices, long runs using inexspensive
phone extension cords, phone line surge surpressors, or couplers) with no telephony
devices (answering machines, fax machines, or portable phone; as well as; older
phones) running to the walljack. The walljack should be wired directly to the
Dmark outside the house with no splices if possible. Other causes are rusty terminals
in the Dmark, wire detetioration, large appliances near exsposed lines, shorts
(or grounds), AML (or similar shared phone services), problems in the loop, a
bad pole card, older equipment on the pole, engineering issues (end of run etc...),
a bad phone jack, or weather/nature. |
| Why
are software modems bad? |
They aren't
"bad", but there are some inherent architectural flaws in the modem
design itself. Software
modems are either missing chips (parts) that control data flow (controller), actually
process data (data pump), or as with the HSP they have
neither. Instead of using chips to process this data those functions are done
with software running in the background. The first problem is that the program
running in the background uses up system resources (see the next row for more
information). Secondly, because of software emulation any line noise/errors that
due occur could potentially back up and cause you to get disconnected. Emulation
is much slower than real chips/hardware so it is slower to correct errors and
therefore more prone to disconnects. A hardware modem will always outperform a
software modem. For a more in depth look at software modems read this. |
| What
else could knock me offline besides line noise/driver issues? |
An outside
application running on your computer in the background that is using up system
resources leaving your PC with limited ability to correct errors and move data
efficiently. Disable
any screensavers, instant messaging programs, icons in your system tray, or any
other program that isn't needed. In general, when you hit CTRL+ALT+DEL on your
keyboard you should only have Systray, Explorer, and Rund32.dll running in Windows
95/98 at start up. Check with your computer manufacturer's tech support for more
information on disabling background programs on start up and how to optimally
configure system resources. Also make sure your video drivers are up to date.
To find out if you have the latest drivers contact your video card/PC vendor or
search their web site. Also try disabling all power saving features in both your
PC BIOS and in the Windows Control Panel "Power Management" feature.
Please contact your PC vendor for more information on how to do this.
|
| Why
can't my local telephone service provider guarantee me a V.90 capable phone line?
|
By Federal
Communications Commission Law a local telephone service provider in the USA only
need provide a signal capable of fax transmission (9600bps) for local service.
In addition, there may be engineering
issues in your area that require the telephone provider to share lines among many
users through a technology called multiplexing. Sometimes it is referred to as
AMLII or pair gain. Multiplexed lines will be limited to a connection speed of
26,400bps. Another common issue is if your phone call is routed through more than
two switches. A line signal will not be strong enough when passed through more
than one switch. Finally, users at the end of a telephone run may have less signal
since they are at the maximum engineering limits for line signal quality.
Long distance phone calls are exempt from this issue. A long distance call is
purposely fed more signal so that it can cross continents without voice loss.
As a result long distance ISPs usually enable you to connect when a local ISP
won't. This is due to the difference in line quality between a local and long
distance call. |
| How
do I use Hyperterminal and initialization strings? |
Microsoft explains
how here.
For more information check
out: Hayes
modem AT commands, basic
modem commands, common
AT commands, and How
To Use AT Commands. |
| What
modem/hardware do you recommend for the Internet? |
It has been
our experience that the following hardware works best for Dial-Up Connections:
(Internal) US
Robotics 56K Performance Pro Modem, (External) US
Robotics 56K External Faxmodem, (Mac) US
Robotics 56K External Faxmodem for Mac, and (Laptop) US
Robotics/3Com XJack and PC Cards. |
| Where
can I learn more about modem, FCC standards, and chip sets for V.90 modems? |
Curt's
High Speed Modem FAQ (explains what a UART is and gives information on modems).
Highlights: Check
out what to buy/not to buy, software modems (RPI, windmodems, HSP/soft modems),
and the modem links area. |
| Where
is a list of modem manufacturers or their support/help sites? |
There are several
good lists on the web: Modems
vendors list, 56k.com,
Modem Help.org
Modem Support Sites, and Windrivers.
|
| I
can't find the modem on this page. |
Check out:
More Initialization
Strings. Also look at Modem
Help.Net or Freeserve
Modem Help. We personally
recommend 56k.com and ModemHelp.org
for modem initialization strings and more information about the vendors. |
| I
can't find my modem driver on this site. |
Go to Windriver.com
Modem Drivers. We
are NOT responsible for driver installation. See your modem vendor! |
| What modem
and dial-up troubleshooting sites do you recommend? |
We prefer the
following sites:
www.56k.com, www.v90.com,
V.90=Unreliable,
ModemHelp.org, ModemHelp.com,
and Windrivers.com. |
| How fast is
my connection? |
Check out a
speed test pages: MSN's
Computing Central by ZDNet or WOL's
Speedtest page. |
| Click on a
connection manager dialer brings up the error: The Service Profile is Damaged. |
Fix here.
The easier way to fix this issue is to create a new dialer using Windows DUN "Make
a new connection". |
| Error: No response
from modem. |
Modem is tied
up by another application or is stuck in a programming loop. First try a complete
shut down. If modem still doesn't respond make sure the correct modem definition
is set up in the dialer and modem control panel. A last ditch resort is to simply
remove the modem and reinstall the driver per the manufacturer's recommendations. |
| Why can't I
save my password in my Windows 9x/Me DUN dialer? |
This is cause by a Windows
Profile issue. Try this:
- Go to Start--> Settings-->
Control Panel--> Network.
- Client for Microsoft Networks
should appear in the list. If not, add it by clicking Add--> Client--> Add-->
Microsoft--> Client for Microsoft Networks.
- Under "Primary Network
Log On" select "Windows Log On". Click "OK". Click "Yes"
to reboot when prompted.
- In the Control Panel click
on Passwords. On the "User Profile Manager" tab it should be set to
"All users of this computer use the same desktop settings and preferences".
Click "Ok". If prompted to reboot do so.
- Go to Start--> Log Off
(Some versions of Windows you must go to Start--> Shut down--> Close All
Programs and Log on as a new user).
- When prompted for a Windows
user name and password enter a new user name, but leave the password empty. Click
"OK". If it asks to confirm the password click "OK" again.
- Bring up your dialer, enter
the user name and password assigned by your ISP, and click on "Save Password".
|
