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/

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

SIXNET
SIXNET offers truly open automation and control solutions including Linux-based controllers, RTUs, Ethernet switches, modular I/O, industrial modems and more.
http://www.sixnetio.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/

Datacom Technology
Get all of your Industrial GSM solutions, Radio Systems, Telemetry products, power supplies, PLC's, Programmable Logic Controllers, shaft power monitors and DC injection brakes from Datacom Technology
http://www.4datacom.co.uk/

S.I. Tech
SI TECH manufactures fiber optic modems, multiplexers, repeaters, cable assemblies, and other communication equipment for LAN, WAN, and Industrial Applications.
http://www.sitech-bitdriver.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/

Cypress Solutions
Cypress Solutions, Rugged Data Modems, CDMA Modems, EV-DO Modems, Cellular Modems, Vancouver Canada
http://www.cypress.bc.ca/

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