Create a SMPP server, based on [url removed, login to view] language. It will be created to handle about 500 TPS (transactions per second).
That software need to be integrated to our current database (MySQL) tables. Validate users, check routing table, user balance, route price, etc.
We already have a SMPP server running, developed in PHP, but it's totally unstable. The new SMPP server must do same tasks of it (eg.: check SMS price and user balance before allowing user to submit messages to server).