Problems with UDP connections

Blitz3D Forums/Blitz3D Programming/Problems with UDP connections

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Hi, for the past month or so I've been working on a networking library of mine. It's somewhat like BlitzPlay, in that it's designed to handle as many networking issues as possible. So far it's working fairly well, and all tests on a local machine work fine. However, I've run into problems with other people not being able to send or receive any messages at all.

I've written a program I call DistriChat, which is a p2p-style chat system. It uses GNet to find one PC, then once it's connected to that user, it shares the remaining IP addresses of all other connected users. If the 'host' user, the one with their IP listed on GNet, leaves, a new user will become the host.

So far I have had a few people able to connect and chat with me, using my program. However others are able to find the proper IP address from GNet, but cannot connect to any other users. This problem seems to happen to more people than I am able to connect with.

I can't say I know a whole lot about routers or firewalls so it might actually be a problem with the PCs I use (I don't own a PC of my own, I rely on the computer labs at my university). My programs mostly use 7000, but my library will increment its port number repeatedly, if a given port number is unavailable (as decided by Blitz's CreateUDPStream() ).

Should I simply start with a different port number or is there something seriously wrong here?