I need an SMPP Gateway engine for SMSC preferably written in Delphi (if not, dot net). The gateway should be able to:

1. Uses robust sockets and able to concurrently maintain connection with up to 1000 SMPP clients.
2. Authenticate SMPP clients using username/password stored in the database.
3. Respond to Submit SM and Enquire link requests from SMPP clients.
4. Terminate connections of clients that are dormant(no enquire link).
5. Decode Submit SM messages (concatenated/unicode) and execute SQL statement for further processing of the message content/destination/source address being decoded.

Note: The SMPP gateway for SMSC is not an SMPP client - it acts similarly to SMPP simulator such as SMPPSim from http://www.seleniumsoftware.com/

You may propose to use open source software that can meet the requirement. A test is required.