Some context

So why might you, if you are operating a cPanel-based VPS for your own Drupal sites, want to consider switching from suPHP to DSO ?

"Your Drupal site got hacked ? Well it's entirely your own fault ! You should always do your updates ! You've only got yourself to blame (and don't dare blame the security holes in that older Drupal code) !!!"

This Gammu module supports external database access, thus you can use it on a VPS-Client without access to COM Port directly. This documentation explain how to use Gammu on VPS:

Many people want to focus on building their Drupal sites and prefer to host their sites with companies that manage the servers and software environments for them. However, sometimes people might need or be interesting in setting up their own server. Recently on LinkedIn there was a discussion of what a 'home brew' Drupalist needs to know to move from shared hosting to a do-it-yourself virtual private server (VPS).

With a VPS you have administrative control over your server (software, not the hardware). This gives you a lot of flexibility and freedom that you might not have with some shared hosting plans, but it also involves more work. If you want to administer your own VPS you should be committed to keeping your site up to date and current with patches, upgrades and security releases, things that a shared hosting service might take care of for you.