Westermo Sales
Westermo is your premiere supplier of high quality, robust data communications equipment designed for harsh industrial applications. They manufacture a wide range of industrial GSM, GPRS, PSTN and ISDN modems.
http://www.westermosales.com

Telenetics
Manufacturer of industrial grade modems, cellular modems, fiber optic line drivers.
http://www.telenetics.com/

U.S. Robotics
USRobotics is rapidly expanding its category leadership by offering high-speed, broadband modems; wired and wireless networking solutions; and Internet security devices to the growing home, home office, and small- and medium-sized business markets. Choose your region.
http://www.usr.com/

Eicon Networks
Dialogic Corporation is a leading provider of world-class multimedia and signaling technologies and platforms that enable its customers and partners to provide innovative mobile, video, IP, and TDM solutions for Network Service Providers and Enterprise Communications.
http://www.eicon.com/

How Stuff Works: Cable Modems
Learn about cable modem technology, read cable modem reviews and compare prices and features on popular modem models.
http://www.howstuffworks.com/cable-modem.htm

Motorola Cable Modems
Makers of the DOCSIS compliant and proprietary cable modems.
http://broadband.motorola.com/noflash/cablemodems.html

Tactical Software, LLC
Offers COM Port Redirector software using public Internet protocols to access shared modems or serial lines, create a modem-sharing server, and replace modems through the use of network connectivity.
http://www.tacticalsoftware.com/

Spirit Corp. - DSP Software Source
SPIRIT delivers embedded voice and communication software products and consulting services to the world's leading telecommunication OEMs, semiconductor suppliers and software vendors
http://www.spiritcorp.com

DCB Inc.
Multiplexers, Data Comm for Business, Inc. Manufactures LAN/WAN, Remote Access, Modems, Statistical Multiplexers and DSUs.
http://www.dcbnet.com/

Internal Modems in Laptops with Linux
A compatibility survey of internal modem devices used in laptops, motherboards and PDAs and their Linux status. As well as tips and tricks to get them identified and working with your laptop or notebook.
http://tuxmobile.org/modem_linux.html