If you intend to run the modem on your DOS partitions, consider the software for that aspect only. As a general rule, if a modem works with DOS, it will work under Linux. When you install the modem, specify the serial port name, and Linux can work with the modem. A modem can work equally well with both operating systems. A common problem in choosing from today's modems is the plethora of acronyms, speeds, and features that are touted for different modems.
Compression algorithms are the current fad in the market.
They use sophisticated mathematical systems to pack as much as five times as many bits per second along a line. For this reason, everyone seems to want data compression in modems, but most users don't realize that the compression scheme must be identical on both ends of the line, or the default speed is the best a modem can achieve. V.FC modems are usually used with data compression schemes to boost the effective throughput to speeds as high as 115kbps. V.FC was developed as a project between Hayes Microcomputer Products and Rockwell. Over 100 modem manufacturers have agreed to accept it as a working standard.