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Answers to Common Problems regarding your modem...
I keep getting
disconnected from the system. Are you guys kicking me off?
What can I do about it?
When using a modem to access on-line services, there
will almost invariably be an occasional disconnection. If
this is a chronic problem for you, this document will help
you find out what's causing the disconnections, and what you
can do about fixing it.
One of the most common reasons for disconnection problems
is line noise. When there is extended static or noise on a
phone line, or the signal becomes very weak, the two modems
exchanging data can't "understand" each other. Most modems
will pause when there is noise on the line and wait to recover
the connection, but occasionally this is not possible, and
the modems will disconnect from each other.
From USR's web site:
"Dropped connections can occur when there is a sharp
decrease in line quality during a call. [28.8] modems will
switch to rates as low as 4800 bps to compensate for these
changes. If the loss of quality is extremely severe, they
will drop the connection."
There are often severe changes in line conditions during
and after inclement weather: moisture in the ground caused
by storms, flooding or snowfall will typically make connections
less reliable. There are many other conditions that might
affect line quality: if you have tried all of our suggestions
in this document and still experience disconnect problems,
you may want to contact your telephone company's repair department.
Some older 28.8 modems are not as capable of holding
connections with bad line conditions: these are known as v.FC
modems. If you have a modem that supports v.FC but not v.34
for 28.8 connections, that may be the cause of your problem.
You can get this information out of your modem's manual. Most
modem manufacturers offer an upgrade that will allow you to
upgrade your v.FC modem to a v.FC/v.34 compatible or even
to the new V.90 standard; contact your modem's manufacturer
for details.
Also, there are often occasions where the firmware for
a particular modem (i.e., the software that "runs" the modem)
is prone to disconnects. In the past, problems of this sort
have appeared with Supra firmware upgrades to turn their 28.8
modems into 33.6 modems, and on early X2 modem models. If
you are experiencing disconnects and have either a new modem
or recently updated your modem's firmware, you might want
to check with your modem manufacturer to see if a fix, updated
firmware, or updated software has been released.
Another common reason for lost connections is call waiting
- the call waiting "beep" on the line is interpreted by modems
as noise on the line, and can eventually cause a disconnection.
In most areas, you can turn off call waiting by adding *70,
before the Bluebonnet's phone number (if this does not work,
check with your local carrier about the procedure to turn
off call waiting while on the Internet).
Also, by default, all dial in accounts only allow ONE
concurrent connection online. So, if you are online your account,
and someone else tries to log on with your account, you may
get disconnected. Make sure you are the ONLY person logging
on to your account and you should be ok.
Some modems are better than others at holding connections.
We've rarely seen problems with US Robotics brand modems (except
one particular model -- see the section on RPI below) or Zoom
modems. However, some are more likely to sporadically disconnect:
modems by Hayes (esp. Hayes Accura), Practical Peripherals,
and software modems, such as the Rockwell/Conexant,LT WinModem
and HSP modems are more likely to experience problems of this
sort.
Some older cordless phone and fax machines use capacitors,
which are prone to send surges of electricity across the phone
connections that those units are attached to: such a surge
can easily knock a modem user off-line. If all of the above
measures have failed, you may want to disconnect all of your
other phone and fax equipment from the line for testing to
see if possibly one of your other telecommunication devices
is knocking you offline.
Sometimes
a high-speed (56k) modem may experience one or more of the
following when trying to connect:
The
modem dials, but handshaking tones continue in loop until
a timeout or no carrier error occurs.
The modem dials and handshaking completes, but the computer
never gets a response from the modem indicating a connection,
eventually getting a no carrier error.
The modem may connect at a speed greater than 33,600 bps but
the connection is very slow or unstable.
In nearly every case, this is due to phone line quality issues
preventing a stable 56k-class (v.90, KFlex or x2) connection.
Unfortunately, there is little that can be done to improve
the quality of the line. However, in most cases a stable connection
at 33,600 bps or slightly less can be achieved by disabling
the 56k feature of the modem.
The
modem setup command (sometimes called modem initialization
string) for the modem must be changed to achieve this. For
connections that use Windows® Dial-Up Networking, or other
programs that use standard Windows modem drivers (generally,
those that display your modem when asking how to dial rather
than asking what COM port to use).
Solution
Click
on Start |Settings | Control Panel.
Double-click the Modems icons.
Click the Properties button.
Click the Connection tab.
Click the Advanced button.
Select the appropriate command from the list below and type
the command into the Extra Settings box.
The appropriate modem command will vary according to the type
of modem:
For
older 3Com® or U.S. Robotics® modems that have not
been updated to v.90, use s32=32.
For newer 3Com or U.S. Robotics modems, or those that have
been updated to v.90, use s32=98.
For LucentTM-based modems, use -v90=0 (those are zeroes, not
the letter O).
For non-PCI Rockwell®-based modems (many 3rd party modems
use Rockwell chips), use +ms=11,1.
For PCI Rockwell-based modems, including the Aztech® "MDP"
series modems, use +ms=v34.
For other modems, check with the modem manufacturer.
PLESE
NOTE:
While this will disable speeds above 33,600, it will usually
allow stable connections on lower-quality phone lines.
If you
still cannot make or maintain a connection, the next step
is to lower your modem port speed and buffer settings.
To
open the Modems control panel and adjust your settings:
1.
click on the Start button
2. click on Settings
3. click on Control Panel
4. double-click on Modems
5. click on the "Properties" button
6. in the window that opens at the bottom will be Maximum
Speed. The default setting is 115200, change this speed to
57600
7. next click on the Connection tab at the top of the window
8. click on the Port Settings button at the bottom left
9. slide the Receive and Transmit Buffers to low
This
should improve your connection by compensating for telephone
line noise.
BACK TO THE TOP
Help! My 56K modem connects
at 33.6 or less!
The term "28.8 modem" and "56k modem" is a bit misleading.
A more appropriate name for a high-speed, v.34 modem is "28.8
capable modem" or "56k capable modem". A v.34 or 56k modem
does over 2000 line tests when it establishes a connection
to determine the maximum speed of the connection that you're
using.
The maximum speed that your phone line is capable of
is a combination of many factors: the quality of the wiring
of the phone connection, the distance between you and your
phone company's CO (central office), the kind of switching
equipment your phone company has you connected to, and the
way the phone company is routing your call. When all is said
and done, there are few areas that will get consistent 33.6Kbps
and 53,333bps connections. The newer v.34+ and v.90 modems
which support 33.6 up to 56kbps are no exception: while they
are capable of handling speeds that high under optimal line
conditions, the majority of phone lines will only be able
to make a connection less than that speed.
Treat this as a troubleshooting matrix. Go through all
of these steps, and you will have a better than 90% chance
of solving your problems with slow connects.
Bluebonnet's lines are optimized for the highest speeds
possible: as such, connections higher than 28.8 and approaching
53kbps are possible with our service, but only from areas
that have particularly clean telephone service.
While connections at 24k or 26.4k are normal and can
be expected with a 28.8 or 33.6 modem, getting very slow connections,
such as 19.2k connections, may show a problem on your line.
You may want to call your phone company's residential repair
department for a free line test if you get consistent slow
connections.
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THE EASY ANSWERS
Things that are easy to try even if you don't
know much about computers. Don't skip this section,
because these fixes often work.
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- If there is a telephone, answering machine, etc.,
plugged into the back of the modem, unplug it from
the back of the modem. The modem is supposed to ignore
devices plugged into it when it is online, but that
is not always the case.
- Try disconnecting additional telephony devices
(fax, phones, answering machines, alarm systems, etc.)
from the phone line, even if they're in a different
room. I've heard from readers whose connect speed
jumped 10K when they unplugged a fax machine or cordless
phone in another room.
- Also try running the phone line directly from
the back of the modem to the wall, without passing
through surge suppressors, splitters, phone line extenders,
etc. This is a basic and useful step in modem troubleshooting.
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MODERATELY DIFFICULT ANSWERS
These require slightly more computer skill.
If you don't know how to use a terminal program, click
on the links for help.
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- DO NOT SKIP THIS NEXT STEP. It's always a good
idea to check the firmware
page to see if there is a more recent firmware
version available. Many people's problems have disappeared
once they installed a new version of the firmware.
- Visit the inits and drivers page
to see if there is an init string or better yet a
driver for your modem. If there is, download and install
it. The inits and drivers page includes installation
instructions.
- If your modem supports more than one 56K protocol,
you may want to tell it which protocol (V.90, x2,
or K56flex) it should use..
- If this is a Rockwell-based K56flex modem, issue
an ATI3 command in a terminal program.
If the version is 1.0 something, you should try adding
S202=32 to your init string.
- If this is a Lucent-based K56flex modem, issue
an ATI3 command in a terminal program.
The firmware version should be at least 4.06, and
higher versions are better.
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OR MAYBE IT'S YOUR PHONE LINE
I was hoping it wouldn't come to this, but it
may not be your modem or inside phone lines at all.
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It may be that the phone lines in your immediate
neighborhood don't support 56K
As explained in the Basics section of the 56K Primer,
multiple digital/analog
conversions will prevent the use of 56K technology
and limit your modem to V.34 speeds (a maximum of 33.6K).
"It's not my phone lines. I know they support
56K"
OK, how do you know your phone lines support
56K? 3Com's
line test is not guaranteed. It can tell you that
your phone line supports 56K when in fact it doesn't,
and vice versa. Don't put all of your faith in it. If
you must use the test line, 3Com recommends calling
it multiple times (ten times, say). On some calls it
may say your line supports 56K and on other calls it
may say the opposite.
The fact that your modem can connect at 56K speeds
to a long distance number is no guarantee that the same
is true of local numbers, and vice versa. Long distance
calls may be routed through telephone circuits which
are significantly better or significantly worse than
the local circuits used to connect to your ISP.
How to find out for sure if your phone lines
support 56K
This is the only reliable way I know of to test
your phone lines: borrow a known good 56K modem and
try it with your phone lines. By "known good 56K modem,"
I mean a modem that has connected at speeds higher than
33.6. Remember that connects speeds of 38400, 57600,
and 115200 aren't true connect speeds, so they don't
count.
If it's an internal modem, have your friend bring
the whole computer to your house. In fact, it's easier
that way, because his computer will already be configured
for his modem. Let him use your monitor, keyboard, and
mouse so he won't have to cart them over to your house.
If you can only borrow the modem, be sure to get
the disks that came with the modem so you can install
the drivers for that modem. You'll have to install the
modem and drivers. Be sure to select the modem in your
dialing software (such as Windows 95 Dial-Up Networking
or Apple's PPP for Open Transport). Instructions are
on the Inits and
Drivers page.
Once his modem is at your house, call his ISP.
How fast is the connection? You can also try calling
your ISP, if your ISP and your friend's modem use the
same 56K protocol (x2, K56flex, or V.90).
More about multiple digital/analog conversions,
and what to do about them
Office PBX systems generally create an extra A/D
conversion. How do you know if you're on a PBX? If you
have to dial a number (usually 9 in the U.S.) to dial
an outside line, you're on a PBX. If your phone has
its own extension, you're on a PBX. The solution in
that case is to plug the modem into a direct outside
line. The office fax machine is usually dialed into
a direct outside line, so try that.
The phone lines outside of your building may have
equipment that introduces extra A/D conversions. Non-integrated
SLCs (subscriber line concentrators) are one source.
If that's the case, there's little you can do except
to call the phone company and complain. Before you get
your hopes up, be aware that the phone company is generally
not sympathetic, and only guarantees speeds of 9600
baud or so (the exact answer will vary from telco to
telco). It is worth a shot, though, and some people
have managed to get their phone company to re-route
the lines.
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BACK TO THE TOP
Even if I don't
connect at 56K, I'm guaranteed 33.6, right?
No. In fact, even if you and your ISP were using 33.6 modems,
you still wouldn't be guaranteed 33.6 connects. Few people
get 33.6 connects. A large number get 28800 or 31200 connects,
but many people only connect at 26400, 24000, or even slower.
The phone lines in some areas simply can't support higher
speeds.
If you'd like to try improving the speed, make sure you
have the latest firmware
and drivers/settings files.
Also, try passing the phone line directly from the back of
the modem to the phone outlet on the wall. Passing the phone
line through surge protectors, phones, answering machines,
etc., has sometimes been responsible for slow connects.
Again, though, your phone lines may simply not support
higher speeds.
BACK TO THE TOP
I'm connecting at
38400, 57600, or 115200. Or am I?
No. Those speeds are computer-to-modem speeds (AKA DTE speeds
or port speeds) that you set in your software. What you want
to know is the modem-to-modem speed (AKA connect speed or
DCE speed). Your <-DTE Speed-> Your <-DCE Speed->
Remote Computer Modem Modem
BACK TO THE TOP
How can I get my
modem to report the true connect speed?
For Windows 95 Dial-Up Networking and Apple's PPP
for Open Transport
You must install the correct drivers for your modem.
For instance, you would need to the correct .inf file for
Windows 95 Dial-Up Networking, or the correct CCL file for
Apple's PPP for Open Transport. The drivers interpret the
result code from the connection and translate it into a connect
speed. Without the driver, you won't get an accurate connect
speed. These may have been included on a disk with the modem.
If not, check the 56K.COM Inits and Drivers page,
which has links to downloadable drivers and instructions for
installing the drivers.
If you have the correct driver/settings file and you
still don't get the true connect speed, add one of the init
strings below to your init string.
For other programs that do not use driver files
According to 3Com/U.S. Robotics, any init string that
includes AT&F1 should report the true connect speed.
For most Rockwell-based 28.8 and K56flex units, the command
is W2. (For Rockwell-based PCI modems, the command is MR=2.)
However, several commands can override W2, including the S95
commands and the &Q commands. If W2 doesn't have the desired
effect, you might try adding S95=0 or S95=1 to the init string.
BACK TO THE TOP
What are typical
connect speeds for 56K modems?
As with 33.6 modems, your results will depend heavily on your
phone lines. To see what kind of performance other people
are getting, see the performance
survey. Typically, 42-46K for K56flex and anywhere from
44-52K for x2 is good performance. Some people are getting
better results, some are getting worse.
BACK TO THE TOP
Is initial connect speed all
it's cracked up to be?
Initial connect speed is a convenient benchmark, but it can
be deceiving. V.34 and 56K modems can and do shift their speeds
up and down during the course of the call to respond to changing
line conditions. Some modems connect very aggressively at high
speeds, but are then forced to lower their speed to a more stable
level. Others may connect conservatively and upshift.
The best test is to download a compressed file with FTP.
BACK TO THE TOP
What's a good way
to test actual modem performance? (FTP downloads)
If done correctly, file downloads are a good way to test
modem performance. The trick is to make sure you're really
testing the modem's raw transfer rate, and not some other
factor that you're not aware of. Here are some guidelines
for download testing:
1. USE AN FTP PROGRAM
Web browsers often lie about download rates. FTP is more reliable.
Note that some FTP programs reports download speeds in Kilobits
per second (Kbps), while others use Kilobytes per second (KBps).
To convert, multiply Kilobytes per second by 10 (eight bits
plus the start bit and stop bit). (V.42 error correction strips
out the start bit and stop bit, but adds other overhead, so
multiplying by nine may be more accurate.) A valid alternative
to FTP is a terminal program that supports Zmodem.
2. DOWNLOAD A PRE-COMPRESSED .ZIP OR .SIT FILE
If the file you download isn't compressed, hardware data compression
in the modem will kick in, leading to erroneous results. Different
file types compress to different degrees, so if you download
a Microsoft Word file and I download a QuickTime movie, there's
no way to compare the results. Use .zip (PKZip/WinZip) or
.sit (StuffIt) files for your tests. Some file formats (GIF,
JPEG, QuickTime, etc.) offer some compression, but can sometimes
be compressed further by hardware protocols.
3. DOWNLOAD A FILE THAT'S AT LEAST 200K
A file size of at least 200K will minimize the effects of
TCP/IP slow start.
4. DOWNLOAD FROM YOUR LOCAL FTP SERVER OR UNIX DIRECTORY
A local server is one that's on your system, not on the other
side of the Internet. If you download a file from across the
Internet, you're testing your ISP's connectivity to the Internet
just as much as you're testing your modem.
Bluebonnet has a FTP site at speed.bluebonnet.net. There
will be a directory called pub that contains downloadable
files. /-->
5. DOWNLOAD DURING OFF HOURS
To eliminate congestion issues, download early in the morning
or late at night.
BACK TO THE TOP
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