DTE Rate - The BPS rate between modem and computer. 56K modems introduce other variable rates between 33600 and 56000. In order to properly use a high link rate, you must set the DTE rate of your computer to the speed that equals or exceeds the Link Rate. Unfortunately, there is little compatibility in implementation between modem manufacturers when it comes to setup commands. This restores the modem to the preferred factory setting.
Some manufacturers have flaws in their factory settings that can actually make things worse.
These modems cannot determine whether or not a modem is actually on-line or not. Granted, many manuals are written poorly and give fairly lame troubleshooting advise, but it still might help you solve a problem. If you have any questions about modems or serial ports, please write to me.