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Note: We have discovered that WinME sends a reset (ATZ) at disconnect. Hyperterminal seems to do this as well. If you want to avoid the possibility of loosing the data from the session, Tor came up with an elegant solution. Unplug the phone cable from the modem after you are done collecting data. Leave the reconnect dialog on screen, while you hook the cable back up and then go into modems, diagnostics, more info and get the register information.

Here's some line test information for use with your USRobotics modem:

Connect for at least 10 minutes and do email, regular surfing. Disconnect. Open Hyperterminal (Start, Programs, Accessories, Hyperterminal). Cancel the connection prompt. You are in the terminal window where you may send commands to the modem.
In terminal mode you can type in the commands listed here to discover facts about the line conditions.

Important factors are: 
          BLERS: Bit Length Error Rate Sample (tossed packets that
                                            had to be retransmitted) 
          Recv/Xmit Level (-dBm)   27.3/13.0  (Signal strength)
          SNR             ( dB )   29.5       (Signal to Noise Ratio)
          Near Echo Loss  ( dB )   9.5
          Far Echo Loss   ( dB )   47.2
          Roundtrip Delay (msec)   4
          Timing Offset   ( ppm)   384
          Carrier Offset  ( ppm)   97
          RX Upshifts              0          (Retrain up Receive rate)
          RX Downshifts            0          (Retrain down Recv. rate)
          TX Speedshifts           1          (Retrain Xmit.)

aty11 gives you a frequency response curve for the entire spectrum required for a modem connection. Drop-off at any level indicates poor line condition. The ATY11 spread printed here is a good one. 50 Hz is somewhat attenuated, then signal levels are even through out the spectrum until you reach 3450 at which point the signal level begins to fall off more quickly. If the attenuation at the top end begins a lot earlier and is even more sever, the phone line is in bad shape.

Signal to Noise Ratio: A Signal to Noise Ratio (SNR) lower than 37 dB indicates a connection with reduced quality. You need a SNR of at least 37 dB in order to sustain a 28.8kbps modem connection, and you'll need a SNR of at least 38 or 39 dB to sustain a 33.6kbps connection.

Receive Level: The Receive Level is the measure of "how loud" the signal from your modem is received by the terminal server. Values between -15 dBm and -25 dBm are good. Values greater (less negative) than -15 dBm may be too "loud" for the terminal server. Values less (more negative) than -25 dBm may be too "quiet" for the terminal server.

Far-end echo: Far-end echo is the portion of the signal transmitted by the terminal server that bounced-off your modem's analog circuitry and came back to terminal server. It is measured in dBm between 0 and -90 dBm. Far-end echo greater (less negative) than -50dBm may be problematic, especially for long-distance calls.

Phase Jitter: The amount of phase difference (out-of-phase) between the transmitted carrier signal and the received carrier signal. (Phase Distortion)

     ati6
        USRobotics Courier V.Everything Link Diagnostics...
                             
        Chars sent                10732      Chars Received            56174
        Chars lost                    0
        Octets sent                6695      Octets Received           49888
        Blocks sent                 492      Blocks Received             520
        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 128/15
        Speed                  21600/19200   <*** Downlink/Uplink speed ****
        Last Call              00:01:39
                             
        Disconnect Reason is DTR dropped  (manually hung up)
                             
          ati11
        USRobotics Courier V.Everything Link Diagnostics...
                             
        Modulation               V.34+
        Carrier Freq    ( Hz )   1959/1959
        Symbol Rate              3429/3429
        Trellis Code             64S-4D/16S-4D
        Nonlinear Encoding       ON/ON
        Precoding                ON/ON
        Shaping                  OFF/ON
        Preemphasis Index        7/1
        Recv/Xmit Level (-dBm)   27.3/13.0     <*** 28/16 acceptable, lower better ***
        SNR             ( dB )   29.5          <*** 26 to 35 acceptable, higher better ***
        Near Echo Loss  ( dB )   9.5
        Far Echo Loss   ( dB )   47.2
        Roundtrip Delay (msec)   4
        Timing Offset   ( ppm)   384
        Carrier Offset  ( ppm)   97
        RX Upshifts              0
        RX Downshifts            0
        TX Speedshifts           1
        V.90 Status
                             
          aty11
        Freq     Level
         150     38
         300     26
         450     24
         600     24
         750     23
         900     23
        1050     23
        1200     23
        1350     23        } flatter response is better ***
        1500     23           levels above 28db are poor
        1650     23
        1800     23
        1950     23
        2100     24
        2250     24
        2400     25
        2550     25
        2700     26
        2850     26
        3000     27
        3150     27
        3300     29
        3450     34
        3600     45
        3750     59

According to 3com/US Robotics subtract the values for 3750 and 3300 (59-29=30 as in the listed values above). If the answer is equal to 25 or greater than 25 then it is very likely that a concentraitor/pair gain on the phone line, and connect speeds above 26,400bps are very unlikely. If the value for 3750 (59 as in the listed values above) is greater than 50 then the local loop is a very long run (their phone line is a long way from the central office) and v.90 connections are next to impossible for the modem to make on the line.

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Phone line testing with reference modem - By Thomas and Tor

Note: We have discovered that WinME sends a reset (ATZ) at disconnect. Hyperterminal seems to do this as well. If you want to avoid the possibility of loosing the data from the session, Tor came up with an elegant solution. Unplug the phone cable from the modem after you are done collecting data. Leave the reconnect dialog on screen, while you hook the cable back up and then go into modems, diagnostics, more info and get the register information.
Here's some line test information for use with your USRobotics modem:
Connect for at least 10 minutes and do email, regular surfing. Disconnect. Open Hyperterminal (Start, Programs, Accessories, Hyperterminal). Cancel the connection prompt. You are in the terminal window where you may send commands to the modem.
In terminal mode you can type in the commands listed here to discover facts about the line conditions.
Important factors are: BLERS: Bit Length Error Rate Sample (tossed packets that had to be retransmitted) Recv/Xmit Level (-dBm) 27.3/13.0 (Signal strength) SNR ( dB ) 29.5 (Signal to Noise Ratio) Near Echo Loss ( dB ) 9.5 Far Echo Loss ( dB ) 47.2 Roundtrip Delay (msec) 4 Timing Offset ( ppm) 384 Carrier Offset ( ppm) 97 RX Upshifts 0 (Retrain up Receive rate) RX Downshifts 0 (Retrain down Recv. rate) TX Speedshifts 1 (Retrain Xmit.)

aty11 gives you a frequency response curve for the entire spectrum required for a modem connection. Drop-off at any level indicates poor line condition. The ATY11 spread printed here is a good one. 50 Hz is somewhat attenuated, then signal levels are even through out the spectrum until you reach 3450 at which point the signal level begins to fall off more quickly. If the attenuation at the top end begins a lot earlier and is even more sever, the phone line is in bad shape.

Signal to Noise Ratio: A Signal to Noise Ratio (SNR) lower than 37 dB indicates a connection with reduced quality. You need a SNR of at least 37 dB in order to sustain a 28.8kbps modem connection, and you'll need a SNR of at least 38 or 39 dB to sustain a 33.6kbps connection.
Receive Level: The Receive Level is the measure of "how loud" the signal from your modem is received by the terminal server. Values between -15 dBm and -25 dBm are good. Values greater (less negative) than -15 dBm may be too "loud" for the terminal server. Values less (more negative) than -25 dBm may be too "quiet" for the terminal server.
Far-end echo: Far-end echo is the portion of the signal transmitted by the terminal server that bounced-off your modem's analog circuitry and came back to terminal server. It is measured in dBm between 0 and -90 dBm. Far-end echo greater (less negative) than -50dBm may be problematic, especially for long-distance calls.
Phase Jitter: The amount of phase difference (out-of-phase) between the transmitted carrier signal and the received carrier signal. (Phase Distortion)

ati6 USRobotics Courier V.Everything Link Diagnostics... Chars sent 10732 Chars Received 56174 Chars lost 0 Octets sent 6695 Octets Received 49888 Blocks sent 492 Blocks Received 520 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 128/15 Speed 21600/19200 <*** Downlink/Uplink speed **** Last Call 00:01:39 Disconnect Reason is DTR dropped (manually hung up) ati11 USRobotics Courier V.Everything Link Diagnostics... Modulation V.34+ Carrier Freq ( Hz ) 1959/1959 Symbol Rate 3429/3429 Trellis Code 64S-4D/16S-4D Nonlinear Encoding ON/ON Precoding ON/ON Shaping OFF/ON Preemphasis Index 7/1 Recv/Xmit Level (-dBm) 27.3/13.0 <*** 28/16 acceptable, lower better *** SNR ( dB ) 29.5 <*** 26 to 35 acceptable, higher better *** Near Echo Loss ( dB ) 9.5 Far Echo Loss ( dB ) 47.2 Roundtrip Delay (msec) 4 Timing Offset ( ppm) 384 Carrier Offset ( ppm) 97 RX Upshifts 0 RX Downshifts 0 TX Speedshifts 1 V.90 Status aty11 Freq Level 150 38 300 26 450 24 600 24 750 23 900 23 1050 23 1200 23 1350 23 } flatter response is better *** 1500 23 levels above 28db are poor 1650 23 1800 23 1950 23 2100 24 2250 24 2400 25 2550 25 2700 26 2850 26 3000 27 3150 27 3300 29 3450 34 3600 45 3750 59

According to 3com/US Robotics subtract the values for 3750 and 3300 (59-29=30 as in the listed values above). If the answer is equal to 25 or greater than 25 then it is very likely that a concentraitor/pair gain on the phone line, and connect speeds above 26,400bps are very unlikely. If the value for 3750 (59 as in the listed values above) is greater than 50 then the local loop is a very long run (their phone line is a long way from the central office) and v.90 connections are next to impossible for the modem to make on the line.