US Robotics
- Go to Start > Program > Accessories > Hyperterminal. (You can install Hyperterminal through Add/Remove Programs if you do not have it).
- Click on the Hyperterm program.
- Name the connection "Test" and click OK.
- Enter the phone number for your ISP connection.
- Ensure that it is set to be using your USRobotics modem, and click OK.
- Click Dial.
- After the handshaking is done, you should see on the screen the word: "Login", though this does vary from ISP to ISP.
- Wait a little while, say 15-60 seconds so you are connected for a bit.
- Disconnect by using the pulldown menu under Call, then select Disconnect.
- After you are disconnected, type ati6, press ENTER, and the following should appear with the 0's filled in:
U.S. Robotics 56K FAX EXT Link Diagnostics...
Chars sent 0 Chars Received 0
Chars lost 0
Octets sent 0 Octets Received 0
Blocks sent 0 Blocks Received 0
Blocks resent 0
Retrains Requested 0 Retrains Granted 0
Line Reversals 0 Blers 0
Link Timeouts 0 Link Naks 0
Data Compression V42BIS 2048/32
Equalization Long
Fallback Enabled
Protocol LAPM/SREJ
Speed 48000/28800
V.90 Peak Speed 49333
Last Call 00:00:00
Disconnect Reason is DTR dropped
Basic Analysis of Ati6:
CLICK HERE for a more advanced/thorough analysis of Ati6.
Here you want to concentrate on BLERs. BLERs are errors in protocol blocks and data received by the modem.
So how many BLERs are too much? If you are getting more than 67 BLERs per minute then you may have trouble with your
line. You should really not be having that high of a BLER count, but it is possible to connect to a server with that number of BLERs and still maintain an OK
connection. While you are looking into repairing that, you may want to lower your connection speed for a more stable connection.
- Next type in ati11, press ENTER, and the following should appear with the 0's filled in:
U.S. Robotics 56K FAX EXT Link Diagnostics...
Modulation V.90
Carrier Freq (Hz) None/1920
Symbol Rate 8000/3200
Trellis Code None/64S-4D
Nonlinear Encoding None/ON
Precoding None/ON
Shaping ON/ON
Preemphasis (-dB) 0/0
Recv/Xmit Level (-dBm) 0/0
Near Echo Loss (dB) 0
Far Echo Loss (dB) 0
Carrier Offset (Hz) NONE
Round Trip Delay (msec) 0
Timing Offset (ppm) 0
SNR (dB) 0
Speed Shifts Up/Down 0/0
Status : 1,2,3,4,5,6,7,8,9,10
Basic Analysis of Ati11:
CLICK HERE for a more advanced/thorough analysis of Ati11.
Here you want to concentrate on SNR and the 8th item under Status. If the numbers for either of the two items are under
40 you may have problems with high speed v90 connections. Below is a chart that
indicates about what speeds will remain stable to semi-stable under an environment with that level of SNR. Note that you
CAN connect at higher speeds with these SNRs, and perhaps lower, and you CAN have a connection without dropped connections,
but the lower the SNR, the more unstable any connection you receive becomes. Though the ratio may be poor, the actual
"damage" that the noise causes can vary from modem to modem, connection to connection.
| SNR Range (Note: SNR = Signal to Noise Ratio) |
Expected "Stable" Speed |
| 40+ |
33,600 - 56,000 |
| 37-40 |
33,600-56,000 (a little unstable at high speeds) |
| 34-37 |
31,200-33,600 |
| 31-34 |
28,800-31,200 |
| 29-31 |
26,400-28,800 |
| 28-29 |
24,000-26,400 |
| 25-28 |
16,800-24,000 |
| 23-25 |
14,400-16,800 (NOTE: If your SNR is around this level or lower the FCC may step in if your telco won't fix it,
this level is not required to be supported, but often is by local teclos and must be upheld if in their charter.) |
| 21-23 |
12,000-14,400 |
| 18-21 |
9600-12,000 (NOTE: If your SNR is around this level or lower the FCC will step in if your telco won't fix it,
this level is REQUIRED, BARE MINIMUM support.) |
| 14-18 |
7200-9600 |
| 13-14 |
4800-7200 |
| 6-13 |
2400-4800 |
| 1-6 |
300-2400 if you are lucky enough to connect. |
This page was last modified on Saturday, 05-Feb-2011 15:13:38 EST.
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