I have kind of a such scenario:

Here i need to synchronize local server database with main DB server(example: computers in office are connected to office server and they use it like a local server, so that no sync is required.BUT computers in other office work with their local server too and we need synchronization between the offices though the main DB server.). As i see i cant use SQLCompact here. Is there a provider to do the server-to-server synchronization right from the client? If no can someone provide a sample of solution of how to manage such situation?