I have been working in the telecommunications industry for many years. I have a lot of experience in telecommunication protocols, call routing, PBXes, switchboards, computer networks, routing and firewalls. I have developed large PBXes based on Kamailio and Asterisk. For the past several years I have been developing using different programming languages, but mainly PHP. I have a lot of experience with MySQL and have used a few other SQL flavors. Telco databases tend to be very large, so query and schema optimization is key. I'm also quite good at regular expressions.