I recently had the oppportunity (necessity) to set up a web application that interacted with many of the users through SMS messages in addition to the more traditional HTML interface. While there are a number of possible software solutions for GSM modems on Windows, on Unix-like platforms the most commonly used one is Kannel. It also has the advantage of being open source and thus very, very free.

However, setting, configuring, and using Kannel tends to be a bit tricky. I’m writing this article (almost a HOWTO) in an attempt to help out anybody who’s undertaking the process themselves and might be able to get some tips and tricks from this. I expect this to not be a terribly popular article, but if I ever need to set this stuff up myself in the future, then I’ll have it written down somewhere at least!

Most of the instructions here will work on any Unix platform, such as Linux, FreeBSD, or Mac OS X. It’s worth noting that I got nearly everything working with OS X, only to be thwarted at the very end because Mac’s no longer have serial ports to use GSM modems. You could, however, easily use some of the more advaned HTTP based SMS services on a Mac server of some sort.