Client / Server connection behind routers or lan

I need a solution that will allow me to connect 2 computers behind 2 different LANs or routers to each other and perform basic client/server functions. Requirements 1. Needs to be written in Visual Basic 6 1. Needs to be internet based. 2. Needs to be capable of transfering large packets. (file transfer) 3. Needs to be commented so I know how to add more functions to it later. 4. I do not care what method you use to acheive this has long as it works. Remember both computers are behind a LAN or router so they will not be able to host a server. Thanks, If you have any questions or suggestions please leave comments. ## Deliverables 1) Complete source code of all work done. 2) Ready-to-run condition on the platform(s) specified in this bid request. 3) Complete ownership and distribution copyrights to all work purchased. ## Platform Windows 9x/2000/XP