This document was intended to give you the best possible modem
connection with a K56Flex or V.90 modem. There are a lot of factors
that can affect 56 Kbps analog modem connections. The steps we've
outlined below should help you get the best possible connection
from your equipment given your line and modem condition.
Verify that your modem is running the latest firmware.
Step 2 Upgrade your modem firmware if necessary.
Step 3 Verify that your modem is using the proper
Step 4 Check your phone line quality.
Step 5 Add an init string to get a more stable
Step 1 - Verify Modem Firmware
To verify your modem's firmware, you will need to use a "terminal
program" to talk directly to your modem. Your system may already
have a terminal program installed with the operating system, or
you may need to download one. Below are instructions on how to use
2 popular terminal programs. You will need to familiarize yourself
with one of these applications to perform a variety of tests.
You will need to determine which "Communications Port"
or "Com Port" your modem resides on. To do this, Click
on the "Start" button, select "Settings", then
"Control Panel". Double-click on Modems. Click on the
"Diagnostics" tab. You will see a list of Com Ports on
the left, and installed components on the right. Note which Com
Port your modem is installed on.
Windows 95/98/ME/XP comes with a terminal program called HyperTerminal.
This application is not normally installed with the operating system,
but may have been installed with Dial Up Networking. To launch HyperTerminal,
click on the "Start" button, select "Programs",
then "Accessories", then "HyperTerminal". If
you do not see HyperTerminal, you will have to install it from your
Windows 95/98/ME/XP installation CD-ROM (see notes)
- Double-click on "Hypertrm" or "Hypertrm.exe".
A new window will appear called "Connection Description".
- Enter "test" into the text box and click "OK".
- A new window will appear called "Phone Number".
"Connect Using" box, click on the popup menu and select
"Directly to com <com port>". Click "OK".
- A new window will appear called "Com <number> Properties".
In the "Bits per second" text box, click on the pop
and select "57600" or "115200" (if supported).
You will now see a large "Terminal" window. You will
commands in to this window to get information from your modem.
You may now skip to "Modem Commands"
Mac OS 7.x/8.x/9.x
Mac OS does not currently include a terminal program. You may have
a program called Zterm that may have been included with some modem
or fax software. To see if you have Zterm, click on the desktop,
then from the "File" menu, select "Find". In
the "Find File" text box, type "zterm" (no quotes)
and click "Find". If no items are found, you will need
to download a copy from here.
You will now end up with a folder call "Zterm 1.0.1".
In this folder, double-click the "Zterm 1.0.1" icon while
holding down the "Shift" key. Select the port your modem
is connected to. You will now see a large "Terminal" window.
You will type commands in to this window to get information from
Modems have "AT Commands" that you can use to get
configuration information from the modem, or even control the modems
behavior. These command are not case sensitive, but it is recommended
that you use upper or lower case exclusively (don't mix upper and
To find your modem's firmware revision, you will use the "ATI"
command followed by a number. Depending on the manufacturer,
there may be up to 15 ATI commands, but generally the firmware revision
number is contained in the "ATI3" or "ATI7"
command. Type these commands into this Terminal Window and write
down the result. Firmware revisions usually contain a "V"
in the number. Modems using the 3Com/USR chipset may not contain
this information, and you may need to download their "Wizard"
program to determine if your modem needs to be upgraded.
Step 2 - Upgrade Your Modem
To upgrade your modem, you will need to visit the manufacturers
website to download a "Wizard" or "Flasher".
These are programs that will update the modem's firmware, the software
that runs the modem. Included with most updates, are special modem
drivers and update instructions that you will need to update and
reinstall your modem. A common mistake is to update a modem without
updating it's supporting driver. This causes a multitude of connection
problems including slow connections or data throughput, and unstable
connections. Using the manufacturers instructions, upgrade the modem
Step 3 - Verify Modem Installation
During the upgrade process, you may have been instructed on how
to update your modem driver, or it may have been
updated automatically for you. Depending on what Operating System
you are using, there may be several ways to update your modem driver.
Below is one example of how to update your modem driver. If you
are sure that your modem driver was installed, you may skip to the
next section "Check Phone Line Quality".
Windows uses an "INF" file to install the modem driver.
You should have an updated "INF" file included with your
modem upgrade. If you do not have one, you can generally download
one from the modem manufacturers site.
To install the modem with a new inf file:
- Click the "Start" button and select "Settings"
then "Control Panel".
- Double-click on "Add New Hardware". Click the "Next"
- Select "No" to the question : "Do you want Windows
for your new hardware?" then click the "Next" button.
- Double-click on "Modem". Check the box titled "Don't
detect my modem; I will select it from a list" then click
the "Next" button.
- Click the "Have disk" button.
- Click the "Browse button"
You will now need to tell Windows the location of the new inf
file. If the inf file is not located on a floppy on A:
drive, you will need to navigate the folder hierarchy to the location
of the inf file. To do this you may need to select your hard drive
from the "Drives" pop up menu. We'll use C: as an example
For example, if your new inf file is on your desktop and you do
NOT have "Profiles" setup in your "Passwords"
control panel, the location would be :
If your new inf file is on your desktop and you do have "Profiles"
set, the location would be :
Please note that depending on how you installed Windows, the "Windows"
folder may be named "Win95".
Once navigating to the correct folder, you will see the available
inf files (there may be more than one). Windows may try to choose
the appropriate file based on the type of hardware you are installing.
- Click the "OK" button on the "Open" dialog
- Click the "OK" button on the "Install From Disk"
dialog box. You will now be presented with a list of modem models.
Select the appropriate model and click the "Next" button.
Select the com port your modem resides on and click the "Next"
- Click the "Finish" button.
You will now need to select the new modem in your "Dial Up
Networking" document. To do this, go to the "My Computer"
window and double-click on the "Dial Up Networking" folder.
Click ONCE on your dialup document called "NetGate" or
"My Connection", then with the right mouse button, select
"Properties". In the "Connect Using" box, select
the new modem. If you desire to delete the old modem, you may do
so via the "Modems" control panel.
Mac OS 7.5.5 or below
Older Mac OS's did not include any PPP or TCP/IP software. You may
have one of a many incarnations of MacPPP or FreePPP. These dialers
use a "Modem Init String" to interact with your modem.
We highly recommend that you upgrade your communications software
to the latest available from Apple's web site. These are the same
components that ship with Mac OS 7.6 and above. If for some reason
you need to use this older software, you will need to obtain the
proper modem init string from the manufacturers website or from
the list that normally accompanies FreePPP or MacPPP. Instructions
on where to put your init string are listed in Step 5.
Mac OS 7.6 or above
Open Transport PPP (OP/PPP) ships with Mac OS 7.6 and later and
is recommended for the best modem connectivity. If you are using
MacPPP or FreePPP, you should remove it and install OT/PPP if it
was not already installed. OT/PPP is the "PPP" control
panel (NOT "ConfigPPP"). OT/PPP uses "Modem Scripts"
or "CCL's" to communicate with your modem instead of "Init
Strings". One or more "Modem Scripts" should have
been included with you modem upgrade, if not you can download one
from the modem manufacturers website. These scripts are often referenced
as "ARA Scripts" or "CCL's" as these were originally
designed to work with "Apple Remote Access".
To install a new modem script, simply drop it into the "modem
scripts" folder in the "Extensions" folder. The "Extensions"
folder is located in the "System Folder" on your hard
drive. Next, open the "Modem" control panel and select
this new modem script from the list of modems. This new script will
tell your Mac how to communicate with your 56k modem.
Step 4 - Check Phone Line Quality
If you you are still not getting a fast connection, it could be
a problem with the quality of your phone line, or you may just live
in an area where 56k connections are not possible. If you see a
connect speed of "38400", "57600", or "115200",
you may not have installed your modem properly and will need to
follow step 3.
Depending on the type of modem you have, the "AT Command"
may be different to determine the integrity of your phone line.
You will need to use a "Terminal Program" to talk to your
modem (Instructions in step 1.). Most 56k modems use chipsets manufactured
by Lucent, Rockwell, Texas Instruments, or 3Com/USR. If the instructions
below do not work for your modem, you may need to contact the modem
manufacturer for more info. "Soft" modems (these are "budget"
modems that usually sell for half the price of a full featured modem)
do not have the ability to assess line quality. The Lucent "LT
Winmodem" is an exception, however the values returned is poorly
Most terminal programs reset the modem, so you will probably need
to establish a connection first before checking the line quality.
Failure to do this will result in zero values or inaccurate data
that will not represent your actual situation.
To establish a connection, type:
where <number> is the phone number you dial to access the
Internet. You will be prompted for a login upon connecting, you
will want to wait a few seconds and then enter three plus signs
+++ but do NOT hit the Enter key. This will signal the modem to
disconnect the call, you can now check your line quality.
K56Flex Modems (Lucent/Rockwell) except LT
In your "Terminal Program", type in AT&V1 followed
You will be presented with one of the following: (the thing to note
is the Line QUALITY value)
TERMINATION REASON LAST TX data rate HIGHEST TX data rate
LAST RX data rate HIGHEST RX data rate Error correction PROTOCOL
Data COMPRESSION Line QUALITY
Highest SPX Receive State
Highest SPX Transmit Rate
EQM Sum Value
RBS Pattern detected Data Rate Dropped in kbps
Digital Pad Detected
031 < This is too high
If you are seeing a Line QUALITY above the value of 25, then 56K
connections are almost impossible. There is nothing the modem can
do about this condition. All you can do is contact your phone
company and see if they can improve your connection quality.
X2 Modems (3Com/USR)
In your "Terminal Program" type in ATI11 followed
USRobotics Courier V.Everything Link Diagnostics...
Carrier Freq. (Hz) Symbol Rate
Nonlinear Encoding Precoding
Preemphasis Index Recv/Xmit Level (dBm)
SNR ( dB )
Near Echo Loss ( dB )
Far Echo Loss ( dB ) Roundtrip Delay (msec)
Timing Offset ( ppm) Carrier Offset ( PPM)
RX Upshifts RX Downshifts TX Speedshifts V.90 Status
46.3 < this is good
You will be presented with one of the following: (the thing to
note is the "SNR" or Signal to Noise Ratio)
If you are seeing a Signal to Noise Ratio below the value of 25,
then 56K connections are almost impossible. There is nothing the
modem can do about this condition. All you can do is contact
your phone company and see if they can improve your connection quality.
In your "Terminal Program" type in ATI11 followed
Last Connection Initial Transmit Carrier Rate
Initial Receive Carrier Rate
Final Transmit Carrier Rate
Final Receive Carrier Rate
Protocol Negotiation Result
Data Compression Result
Estimated Noise Level
Receive Signal Power Level (dBm)
Transmit Signal Power Level (dBm)
Round Trip Delay (msec)
Press any key to continue; ESC to quit.
Near Echo Level (dBm)
Far Echo Level (dBm)
Transmit Frame Count
Transmit Frame Error Count
Receive Frame Count
Receive Frame Error Count
Retrain by Local Modem
Retrain by Remote Modem
Call Termination Cause
RobbedBit Signaling Digital Loss (dB)
Remote Server ID 4342C3
We're concerned with "Estimated Noise Level" here. This
number is affected by the downstream data rate, so there is no "good"
number to look for, Higher numbers are bad. If you are having trouble
getting a 56K connection, contact your phone company and see if
they can improve your connection quality.
Step 5 - Add an init string to your modem's
If you've made it this far, you will probably not be able to make
a 56k connection, the best you can hope for is a slower but more
stable connection. Adding init strings is an advanced procedure,
and knowledge of how modems work and how they are affected by these
init strings is helpful.
If you modem came with a manual that contains "AT commands",
this will be helpful in whipping up a recipe. There are many sites
on the Internet that document some known init strings that can be
used. You will want to test your these init strings and your connections
via a terminal program prior to modifying your system modem configuration.
Windows 95/98/ME/XP and Mac's using Mac PPP or Free PPP will accept
init strings, if your Mac uses OT/PPP, you will want to download
and install the latest ARA Script for your modem from the modem
manufacturer's website as detailed in Step 3 under MacOS 7.6. Advanced
users could use a program like BB Edit to modify an ARA script,
but this is only necessary in extreme cases.
The first step will be to locate an init string by utilizing the
resources on the Internet, like the modem manufacturers support
area of their website, and/or possibly on of the links below. You
are generally looking for a string that forces a specific 56k standard
(like K56Flex instead of V.90), force a V.34 connection disabling
the use of 56k speeds altogether (V.34 refers to speeds 33.6 and
below), or forces the modem to connect at a specific slower speed
(maybe 38000 for example if connections at that speed appear more
stable. Some options include the disabling of fast retrains, or
forcing the modem to ignore the V.8bis tone (the initial "burp"
tone you hear when you dial a 56k modem pool). You can trick the
modem to ignore the first few seconds of the call by adding commas
after the phone number. Depending on the modem, a comma represents
a 2 second delay before listening to the modem on the other end
of the line. Experiment using one to four commas, this is most helpful
for older non56k modems that do not understand the V.8bis tone.
Launch your terminal program, and enter the init string making sure
to enter AT before the init string (if the string does not already
contain AT). If you receive the response "OK" you are
ready to test your connection. If you received "ERROR"
the init string you selected is invalid for that type of modem,
or you made a typo.
To test your connection, type:
where <number> is the phone number you dial to access the
Internet You will want to pay particular attention to the negotiation
of the modems (the sounds) to see if the modem connects easily,
or has to continually retrain to establish a connection. Once you
determine an init string that works for you, you will want to enter
it into your dialup software.
Go to the "My Computer" window and double-click the "Dial
Up Networking" folder. Click once on your appropriate dialup
document and access the "Properties" by clicking on the
file menu of the surrounding window, or by clicking on the document
with the right mouse button. Click the "Configure" button
near the modem icon. Click the "Connection" tab, and then
the "Advanced" button. Enter your modem init string in
the "Extra Settings" box. Preceding the init string with
AT is optional.
Mac OS using MacPPP or FreePPP
Launch the "Config PPP" control panel and click on the
"Config" button. In the text box labeled "Modem Init",
enter your init string ensuring that the string starts with AT as
described above. Click the "Done" button. You should now
be able to connect by clicking the "Open" button. If this
button is Gray, you init string is not valid, the PPP extension
is not installed, or PPP is not selected in your MacTCP or TCP/IP
Useful Links to Modem Web Sites
A good site for LT Winmodems, but has plenty of information on other
Mostly covers V.90 modems and has information on how the telephone
The official 56K Modem Web Site ( Has links to modem manufacturer's
Modem Central ( Has links to sites with init strings )
The Unofficial PortMaster Repository (Has INIT strings to use as