Forums | USR | Limiting Link Speed | Watch |
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jimbo62 Tl Posts: 23 USA | Posted - 11/24/2003 12:42:01 PM 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 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
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charles Tl Posts: 5879 USA | Posted - 11/24/2003 1:12:53 PM 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 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 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 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 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 Post the command that you are using. This is a OEM modem model 1749 http://www.usr.com/support/product-template.asp?prod=oem
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jimbo62 Tl Posts: 23 USA | Posted - 11/30/2003 5:55:21 PM 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 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 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 at Chars sent 20529 Chars Received 153598 Retrains Requested 0 Retrains Granted 0 Data Compression V42BIS 2048/32 Disconnect Reason is DTR dropped OK
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charles Tl Posts: 5879 USA | Posted - 12/1/2003 11:31:30 AM 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 I'd suggest experimenting in Hyperterminal - gives you better control & ability to see results. Try try various combos....? Also verify the &N/U values via the help screen
Aloha! Richard. |
jimbo62 Tl Posts: 23 USA | Posted - 12/1/2003 4:24:24 PM quote: |
jimbo62 Tl Posts: 23 USA | Posted - 12/2/2003 2:03:12 PM &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 Try ATI4 and ATI5 in hyperterminal.Display the current modem settings
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