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jimbo62
Tl Posts:
23

USA
Posted - 11/24/2003 12:42:01 PM  Show Profile  Email Poster  Edit Message
I have a US Robotics 56K Voice INT modem, ID 66174981, Python, that came factory installed in a Dell desk top. It is V.90 capable. I have been told by a USR tech that it is in the Sportster family.

I have been running extensive diagnostics in recent days because of a slow connect/throughput speed problem that was caused by a Radio Shack phone. While the bad phone was connected I was able to use AT&Nn to limit connect speed and see the effect on throughput. But since I have ditched the bad phone, AT&Nn does not limit speed or throughput. My modem always connects at 50.666 kbs and the throughput is always 43-45 kbs. Not that I am complaining about the performance, but I was doing further experimentation to see if I could squeeze out a little higher throughput by limiting the speed via AT&Nn. But as I said, no matter what I put in for a limit, it always connects at 50.666 kbs and the throughput is always 43-45 kbs. I have also used AT&Un as a lower limit along with AT&Nn for the upper limit with no success at limiting the speed. Any insight as to what might be going on would be appreciated.

As a separate question, where can I get the AT comand set for this modem? I have printed out the commands via AT$, AT&$, etc. but a more detailed description of the commands would be helpful.

Regards, jimbo

charles
Tl Posts:
5879

USA
Posted - 11/24/2003 1:06:44 PM  Show Profile  Email Poster  Edit Message
Are using these together?

You do not need the AT in the command if using in extra settings.The string would &Un&Nn use these toghter. reboot before making connection.You can also look in the miodem inf file.

http://modemsite.com/56k/x2-linklimit.asp#3Com

http://www.usr.com/support/698/698-files/1153-00.pdf
http://www.usr.com/support/3056/3056-ug/five.html

charles
Tl Posts:
5879

USA
Posted - 11/24/2003 1:12:53 PM  Show Profile  Email Poster  Edit Message
http://www.modemhelp.net/quickref.shtml
http://www.usr.com/support/3cp3056/3cp3056-ug/atcoms.htm
charles
Tl Posts:
5879

USA
Posted - 11/24/2003 1:14:20 PM  Show Profile  Email Poster  Edit Message
http://www.usr.com/support/3cp3056/3cp3056-ug/3056-6.htm

just click on the arrow at the top left.

jimbo62
Tl Posts:
23

USA
Posted - 11/24/2003 3:56:27 PM  Show Profile  Email Poster  Edit Message
The exact string that I used and that shows up in the modem log just before the dialing sequence is: AT&U17&N20

I was not aware that the computer had to be re-booted before these settings took effect.

Regards, jimbo

jimbo62
Tl Posts:
23

USA
Posted - 11/26/2003 10:31:56 AM  Show Profile  Email Poster  Edit Message
Well, I have tried rebooting after a change in the sting to limit speed with no change in the result. No matter what speed limits I use, the modem always connects at 50.666 kbs and the throughput is always 44-45 kbs. Can the ISP's modem override my modem setting? Or is there another setting somewhere that allows the modems to negotiate higher speed limits if a "good" connection is established?

Also, where should I look for the modem inf file? There are hundreds of inf files in Windows/inf directory, which one would be the file for the USR modem?

Regards, jimbo

charles
Tl Posts:
5879

USA
Posted - 11/27/2003 8:38:33 AM  Show Profile  Email Poster  Edit Message
no the isp has no control over your modem commands.Are using any isp connecting software like AOL? Will the modem work with commands hyperterminal?
charles
Tl Posts:
5879

USA
Posted - 11/28/2003 11:07:29 PM  Show Profile  Email Poster  Edit Message
Post the command that you are using. This is a OEM modem model 1749

http://www.usr.com/support/product-template.asp?prod=oem
http://www.modem-help.com/mfcs.php?mid=1&nid=4136

jimbo62
Tl Posts:
23

USA
Posted - 11/30/2003 5:55:21 PM  Show Profile  Email Poster  Edit Message
The exact string that I used and that shows up in the modem log just before the dialing sequence is: AT&U17&N20. Despite this limit, the modem connects at 50.666 kbs and the measured throughput is 44-45 kbs.

Regards, jimbo

jimbo62
Tl Posts:
23

USA
Posted - 12/1/2003 8:30:14 AM  Show Profile  Email Poster  Edit Message
Just a follow up to your other questions. No, I don't use anything like AOL, just a standard ISP. And yes, HyperTerminal works just fine with the modem. I will post a modem log later today. And I could also post ATI6, ATI11 and ATY11 if that would be helpful.

Regards, jimbo

jimbo62
Tl Posts:
23

USA
Posted - 12/1/2003 11:00:56 AM  Show Profile  Email Poster  Edit Message
OK, here is the modem log, followed by ATI6 and ATI11.

Regards, jimbo

12-01-2003 10:05:06.70 - Modem type: U.S. Robotics 56K Voice INT PnP
12-01-2003 10:05:06.70 - Modem inf path: 3COMMD~1.INF
12-01-2003 10:05:06.70 - Modem inf section: ModemVIn90
12-01-2003 10:05:06.96 - 115200,N,8,1
12-01-2003 10:05:06.96 - 115200,N,8,1
12-01-2003 10:05:06.96 - Initializing modem.
12-01-2003 10:05:06.96 - Send: AT<cr>
12-01-2003 10:05:06.96 - Recv: AT<cr>
12-01-2003 10:05:07.08 - Recv: <cr><lf>OK<cr><lf>
12-01-2003 10:05:07.08 - Interpreted response: Ok
12-01-2003 10:05:07.08 - Send: AT&F1E0Q0V1&C1&D2S0=0<cr>
12-01-2003 10:05:07.08 - Recv: AT&F1E0Q0V1&C1&D2S0=0<cr>
12-01-2003 10:05:07.21 - Recv: <cr><lf>OK<cr><lf>
12-01-2003 10:05:07.21 - Interpreted response: Ok
12-01-2003 10:05:07.21 - Send: ATS7=60S19=0L0M1&M4&K1&H1&R2&I0B0X4<cr>
12-01-2003 10:05:07.34 - Recv: <cr><lf>OK<cr><lf>
12-01-2003 10:05:07.34 - Interpreted response: Ok
12-01-2003 10:05:07.34 - Send: AT&U17&N20<cr>
12-01-2003 10:05:07.46 - Recv: <cr><lf>OK<cr><lf>
12-01-2003 10:05:07.46 - Interpreted response: Ok
12-01-2003 10:05:07.46 - Dialing.
12-01-2003 10:05:07.46 - Send: ATDT;<cr>
12-01-2003 10:05:09.00 - Recv: <cr><lf>OK<cr><lf>
12-01-2003 10:05:09.00 - Interpreted response: Ok
12-01-2003 10:05:09.00 - Dialing.
12-01-2003 10:05:09.00 - Send: ATDT#######<cr>
12-01-2003 10:05:32.48 - Recv: <cr><lf>CONNECT 50666/ARQ/V90/LAPM/V42BIS<cr><lf>
12-01-2003 10:05:32.48 - Interpreted response: Connect
12-01-2003 10:05:32.48 - Connection established at 50666bps.
12-01-2003 10:05:32.48 - Error-control on.
12-01-2003 10:05:32.48 - Data compression on.
12-01-2003 10:06:50.66 - Hanging up the modem.
12-01-2003 10:06:50.66 - Hardware hangup by lowering DTR.
12-01-2003 10:06:50.78 - Recv: <cr><lf>NO CARRIER<cr><lf>
12-01-2003 10:06:50.78 - Interpreted response: No Carrier
12-01-2003 10:06:50.78 - Send: ATH<cr>
12-01-2003 10:06:50.90 - Recv: <cr><lf>OK<cr><lf>
12-01-2003 10:06:50.90 - Interpreted response: Ok
12-01-2003 10:06:50.90 - 115200,N,8,1
12-01-2003 10:06:50.90 - Session Statistics:
12-01-2003 10:06:50.90 - Reads : 153710 bytes
12-01-2003 10:06:50.90 - Writes: 20623 bytes
12-01-2003 10:06:50.90 - U.S. Robotics 56K Voice INT PnP closed.

at
OK
ati6
U.S. Robotics 56K Voice INT Link Diagnostics...

Chars sent 20529 Chars Received 153598
Chars lost 0
Octets sent 11621 Octets Received 133045
Blocks sent 505 Blocks Received 1200
Blocks resent 0

Retrains Requested 0 Retrains Granted 0
Line Reversals 0 Blers 2
Link Timeouts 0 Link Naks 0

Data Compression V42BIS 2048/32
Equalization Long
Fallback Enabled
Protocol LAPM
Speed 50666/19200
V.90 Peak Speed 50666
Last Call 00:01:18

Disconnect Reason is DTR dropped

OK
ati11
U.S. Robotics 56K Voice INT 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) 0/2
Recv/Xmit Level (-dBm) 16/10
Near Echo Loss (dB) 10
Far Echo Loss (dB) 0
Carrier Offset (Hz) NONE
Round Trip Delay (msec) 9
Timing Offset (ppm) -2219
SNR (dB) 0.0
Speed Shifts Up/Down 0/0
Status : uu,5,12N,12.3,-0,0N,0,46.4,29.9

charles
Tl Posts:
5879

USA
Posted - 12/1/2003 11:31:30 AM  Show Profile  Email Poster  Edit Message
Try this string see if it will make a change. Might also reset the modem.

&U12&N25

v.Richard
Tl Posts:
6222

USA
Posted - 12/1/2003 1:26:31 PM  Show Profile  Email Poster  Edit Message  v.Richards Homepage
I'd suggest experimenting in Hyperterminal - gives you better control & ability to see results.

Try
AT&F1
AT&N26
dial-

try various combos....?

Also verify the &N/U values via the help screen
AT&$

Aloha! Richard.

jimbo62
Tl Posts:
23

USA
Posted - 12/1/2003 4:24:24 PM  Show Profile  Email Poster  Edit Message
quote:
Post the command that you are using. This is a OEM modem model 1749

http://www.usr.com/support/product-template.asp?prod=oem
http://www.modem-help.com/mfcs.php?mid=1&nid=4136[/quote]

The link to the modem that matches my modem model number is interesting and puzzling. When I ordered my Dell, I just accepted the "standard" internal modem. When the Dell order taker called to verify, he suggested upgrading the modem to "the best Dell had" because I wouldn't be satisfied with the "standard". I was under the impression that it was a hardware modem, not a Winmodem. Anyway, I upgraded and paid a little more for my system. Now, I find that it is a Winmodem! Well, that may be my last Dell.

Regards, jimbo


jimbo62
Tl Posts:
23

USA
Posted - 12/2/2003 2:03:12 PM  Show Profile  Email Poster  Edit Message
&U12&N25 causes modem to fail to complete the connection. The &U12 speed is in the V34 range, &N25 is in the V90 range. I don't how to reset an internal modem. I though it reset everytime the computer was powered down and up. I have tried AT&F1 ahead of the &U and &N commands. I have tried many variations, using both &U and &N, just &N, AT&F1 prior to any &U or &N commands, high &U limit, high &N limit, etc. In the command descriptions, it says if the modem can't connect at &N limit when &N is used alone, the modem will hang up. It doesn't hang up, it just always connects at 50.666 kbs.

Very frustrating, especially since before I threw out the bad phone, the &N speed limit worked as expected.

Regards, jimbo

charles
Tl Posts:
5879

USA
Posted - 12/5/2003 8:36:19 AM  Show Profile  Email Poster  Edit Message
Try ATI4 and ATI5
in hyperterminal.Display the current modem settings

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