The rates are negotiable and will depend on the extent of work that you need done. The tools themselves will always be free, and the source code, of course will always be freely available, in the true spirit of Linux. It has three classes, TcpClient, TcpServer and TcpIpRuleSet. TcpServer has build it logging capability peer detection method, and IP-based access control in addition to regular server functionality. Download it from here Despite the lack of doucumentation, the sources contain examples that should help you figure it out.
Any suggestions are welcome.
Click here to download. Latest version has IP-based access control option. Search from here. You can set up the same thing for yourself, and make 2 cents every time someone searches.