Compiled by USAonline's Tech Support - Things to do for faster connect speeds.
EASY ANSWERS TO MODEM SPEED QUESTIONS.
Things that are easy to try even if you don't know much about
computers.
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
users 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, (keep it
under 12 ft.) without passing through surge suppressors, splitters, phone line extenders,
etc. This is your first, basic and useful first step in modem speed troubleshooting.
MODERATELY DIFFICULT ANSWERS TO MODEM SPEED QUESTIONS
Lower than normal connect speeds may not be a modem or inside phone line problem at
all. It may be that the phone lines in your immediate neighborhood can't support 56K . Yes
it's true, location may be a big factor. Multiple digital/analog conversions will also
prevent the use of 56K technology and limit your modem to V.34 speeds (a maximum of
33.6K).
How to find out for sure if your phone lines support 56K &
V90
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 you know has connected at speeds higher than 33.6. Remember that connects
speeds of 38400, 57600, and 115200 aren't true connect speeds, they are
"Indicated" speeds, so they are NOT correct.
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.
Are you guaranteed 33.6 ?
No. In fact, even if you and your ISP were only using 33.6 modems (which is not the
case), you still wouldn't be guaranteed 33.6 connects all the time. Few people actually
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.
Your connecting at 38400, 57600, or 115200. Or are you?
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).
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 correct driver, you won't get an accurate
connect speed. These may have been included on a disk with the modem. If not, check the WWW.56K.COM Inits and Drivers page, which has links to
downloadable drivers and instructions for installing the drivers.
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.
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
Is initial connect speed all it's cracked up to be?
Initial connect speed is a convenient benchmark, but it can be very 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. For help with getting accurate
results, see the section below on FTP.
What's the command for connection speed and stats on my
K56flex?
Lucent-based K56flex modems
After disconnecting, issue an AT11 command in your terminal program.
Rockwell-based K56flex modems
After disconnecting, issue an AT&V1 command in your terminal program. These are some
example results. TX is the transmit (upload) speed. RX is the receive (download) speed.
AT&V1
TERMINATION REASON.......... LOCAL REQUEST
LAST TX data rate........... 31200 BPS
HIGHEST TX data rate........ 31200 BPS
LAST RX data rate........... 46000 BPS
HIGHEST RX data rate........ 50000 BPS
Error correction PROTOCOL... LAPM
Data COMPRESSION............ V42Bis
Line QUALITY................ 127
Receive LEVEL............... 014
Highest SPX Receive State... 00
Highest SPX Transmit State.. 00
EQM Sum Value............... 00A2
RBS Pattern detected........ 00
Data Rate Dropped in kbps... 00
Digital Pad Detected........ None
What's the command for connection speed and stats on my USR?
After disconnecting, issue an ATI6 and ATI11 in your terminal program. These are some
example results. Note that the ATI6 Speed line shows the highest download/upload connect
speeds. The ATI11 command shows the number of upshifts and downshifts for receive (RX) and
send (TX).
ATI6:
Chars sent 580 Chars Received 49642
Chars lost 0
Octets sent 360 Octets Received 26533
Blocks sent 191 Blocks Received 805
Blocks resent 0
Retrains Requested 0 Retrains Granted 0
Line Reversals 0 Blers 1
Link Timeouts 0 Link Naks 0
Data Compression V42BIS 2048/32
Equalization Long
Fallback Enabled
Protocol LAPM SREJ 128/15
Speed 46666/31200
Last Call 00:04:34
Disconnect Reason is Escape code
ATI11:
USRobotics Courier V.Everything Link Diagnostics...
Modulation x2/V.34+
Carrier Freq ( Hz ) NONE/1920
Symbol Rate 8000/3200
Trellis Code NONE/64S-4D
Nonlinear Encoding NONE/ON
Precoding NONE/OFF
Shaping OFF/ON
Preemphasis Index NONE/0
Recv/Xmit Level (-dBm) 15.7/12.2
SNR ( dB ) 61.5
Near Echo Loss ( dB ) 10.2
Far Echo Loss ( dB )
Roundtrip Delay (msec) 26
Timing Offset ( ppm) -1406
Carrier Offset ( ppm) 68
RX Upshifts 0
RX Downshifts 1
TX Speedshifts 0
x2 Status 0000; 0000-0000-0001-0000-0000-0000; 00,00 0031;03
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 LIKE WSFTP_LE
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 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) 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 AN FTP SERVER
We recommend ftp.zdnet.com log
in anonymous, then download a random file at least 250k in size.
5. DOWNLOAD DURING OFF HOURS
To eliminate congestion issues, download early in the morning or late at night.
We hope these tips clarify some modem speed issues for you and
help you understand more fully the MANY factors involved in the connect speeds you can get
from your USAonline's account.