This is - Helping you get the best performance from your modem
 Troubleshooting News Technical Search
 Home Forum 56 Premium Site Map
Home Troubleshooting If you get a PORT (115.2k, 57.6k) Connect Report

Modems & Windows .inf Files (Updated 27-Jul-03)

If your dial-up networking (DUNS) CONNECT shows a speed of 57,600 (57.6k), 115,200 (115.2k), or 38,400 (38.4k), you are getting the port speed between your computer and modem, not the modem CONNECT rate.

With Windows 95/98/Me/NT/2K & XP, a file with the .inf extension is used when you install your modem to define how Windows and Windows Programs interact with the modem.

For DUNS to report the correct speed in all cases, every possible CONNECT message must be defined in the .inf file. In addition, some 56k modems with Conexant (formerly Rockwell) chipsets are shipped where the factory default gives a CONNECT of the port speed instead of the carrier rate. For these modems, put W2 in the extra settings of the modem properties (see Init Strings for screen shot of the extra settings advanced modem property.) 

Note: Some modem companies' have released .inf files that do not include all connect rates the modems are capable of! You can still find out what speed you are connecting at. It is also possible to edit the .inf file and add any missing responses so that Windows recognizes and reports the modem connect speed.

Flash modems can be upgraded which give the modem new speeds or protocols, and new CONNECT message possibilities. If you don't uninstall the modem, and re-install it with an updated .inf file, you may no longer get your modem-modem CONNECT rate on DUNS connections. If your modem was never installed with the correct .inf file, you may also get the port speed instead of the CONNECT rate.

Follow this process to enable the correct .inf file. Note: The vendor of your modem should supply you with, or have available for download, the correct .inf file for your modem. You need the correct file, and you need to know where on your system it is located (ie, hard-drive folder, diskette, CD, etc.) This following works only with hardware-controller-based modems - you cannot use this procedure with soft or Win modems:


2. Highlight your modem, then click PROPERTIES. Make a note of the settings, then OK. Click REMOVE

3. After you REMOVE the modem, click ADD...

4. Click - Don't detect my modem, I will select it from a list. Then click Next.

5. On the Install New Modem dialog, click Have Disk... and specify the location of the correct .inf file.

6. Set the modem up with the same values as the old modem had. OK

With many newer modems the above procedure won't work - use this procedure - note this procedure is still for modems that are hardware-controller based and will not work with soft or win modems:

1. Enable Modemlog file.

2. Connect normally to your ISP, then end the call.

3. Open the Modemlog file, and search it for the entry that says: "Modem inf path:" and note the name of the .inf file.

4. Note: this .inf file may be in a hidden directory, often \windows\inf and may not appear with normal Explorer screens. Use Find... as in step 3 to find the .inf file. Make a backup of this file by right-clicking it and dragging it to the desktop or an explorer window, using the Copy here option. Then, delete the .inf file.

5. REMOVE the modem using Control Panel/Modems.

6. REBOOT; Windows Plug and Play will detect the modem and want to add a driver; since the .inf file is missing, it will ask you for a location, and you can now specify the location of the updated .inf file.

AN ALTERNATIVE that will work with any modem, including soft and win modems: if the current and new .inf files have the same name, you can copy the new .inf file to replace the old one in the \windows\inf directory. (Make a backup of the old file first!) This will only work if the new .inf file uses the same .inf section for your modem, .

 You can still determine connect speed with an incorrect .inf file if you enable the Modem Log File. Then, after you are disconnected, open your Modemlog file and you will see the CONNECT report including speed:

07-11-1998 11:18:11.98 - Recv: CONNECT 33333<cr><lf><cr><lf>PROTOCOL: LAP-M<cr>
07-11-1998 11:18:11.98 - WARNING: Unrecognized response. Retrying...
07-11-1998 11:18:11.98 - Connection established at 115200bps.
07-11-1998 11:18:11.98 - Error-control off or unknown.
Notice the "Unrecognized response", then 115k report. Here is the log with a good .inf file:

07-20-1998 06:05:19.440 - Send: ATDT#######<cr>
07-20-1998 06:05:39.188 - Recv: <cr><lf>CONNECT 48000/ARQ/V90/LAPM/V42BIS<cr><lf>
07-20-1998 06:05:39.188 - Interpreted response: Connect
07-20-1998 06:05:39.188 - Connection established at 48000bps.
07-20-1998 06:05:39.188 - Error-control on.
07-20-1998 06:05:39.188 - Data compression on.

Modemlog.txt also shows the name and section of the .inf file being used:

07-11-1998 11:16:54.89 - Creative Modem Blaster DI5600 in use.
07-11-1998 11:16:54.90 - Modem type: Creative Modem Blaster DI5600
07-11-1998 11:16:54.90 - Modem inf path: CREATI~1.INF
07-11-1998 11:16:54.90 - Modem inf section: Creative_26

If you have trouble finding an .inf file for your modem, you may be able to use one for a modem similar to yours - while there are many modem brands and models, there are only a few chipsets and the responses for all modems of a particular chipset will be the same.

It is possible to edit an existing .inf file, but it is tedious. Here's a portion of the .inf file for a V.90-upgraded Courier v.Everything:

HKR,Responses,"<cr><lf>CONNECT 49333/ARQ/V90/MNP/MNP5<cr><lf>", 1,2,3,B5,C0,0,0,0,0,0,0
HKR,Responses,"<cr><lf>CONNECT 49333/ARQ/V90/LAPM/V42BIS<cr><lf>",1,2,3,B5,C0,0,0,0,0,0,0
HKR,Responses,"<cr><lf>CONNECT 49333/ARQ/V90/MNP<cr><lf>", 1,2,2,B5,C0,0,0,0,0,0,0
HKR,Responses,"<cr><lf>CONNECT 49333/ARQ/V90/LAPM<cr><lf>", 1,2,2,B5,C0,0,0,0,0,0,0
HKR,Responses,"<cr><lf>CONNECT 49333/V90/NONE<cr><lf>", 1,2,0,B5,C0,0,0,0,0,0,0
HKR,Responses,"<cr><lf>CONNECT 49333/ARQ/V90<cr><lf>", 1,2,2,B5,C0,0,0,0,0,0,0
HKR,Responses,"<cr><lf>CONNECT 49333/ARQ/x2/MNP/MNP5<cr><lf>", 1,2,3,B5,C0,0,0,0,0,0,0
HKR,Responses,"<cr><lf>CONNECT 49333/ARQ/x2/LAPM/V42BIS<cr><lf>", 1,2,3,B5,C0,0,0,0,0,0,0
HKR,Responses,"<cr><lf>CONNECT 49333/ARQ/x2/MNP<cr><lf>", 1,2,2,B5,C0,0,0,0,0,0,0
HKR,Responses,"<cr><lf>CONNECT 49333/ARQ/x2/LAPM<cr><lf>", 1,2,2,B5,C0,0,0,0,0,0,0
HKR,Responses,"<cr><lf>CONNECT 49333/x2/NONE<cr><lf>", 1,2,0,B5,C0,0,0,0,0,0,0
HKR,Responses,"<cr><lf>CONNECT 49333/ARQ<cr><lf>", 1,2,2,B5,C0,0,0,0,0,0,0
HKR,Responses,"<cr><lf>CONNECT 49333/ARQ/x2<cr><lf>", 1,2,2,B5,C0,0,0,0,0,0,0
HKR,Responses,"<cr><lf>CONNECT 48000/ARQ/V90/MNP/MNP5<cr><lf>", 1,2,3,80,BB,0,0,0,0,0,0


Home  |  Links  |  Send Feedback  |  Privacy Policy  | Report Broken Link
Legal Page  |  Author's Web Sites   |  Log In 1998-2016 v.Richard Gamberg. All rights reserved.