I would like to add a small not on NAT punching that is not discussed in of the papers or sites I read. In brief: - User A connects to matchmaking server and registers a new session. - User A connection info are saved on the server. - User B wants to connect to user A's session so it requests the info from the server. Everything is fine until we face the problem of ISPs blocking or limiting traffic on certain ports. And, it seems some are doing so (in my case) on high ports. If you connect to a remote server everything is fine, but trying to connect to a remote client on port 3128 allocated by the router might sometimes block and this is not a user issue as much as it is ISP/Firewall. It may not be much related to NAT but it affects it much and it is not mentioned so i just wanted to post it.

Quote:Original post by ZeRaW
I would like to add a small not on NAT punching that is not discussed in of the papers or sites I read.
In brief:
- User A connects to matchmaking server and registers a new session.
- User A connection info are saved on the server.
- User B wants to connect to user A's session so it requests the info from the server.
Everything is fine until we face the problem of ISPs blocking or limiting traffic on certain ports. And, it seems some are doing so (in my case) on high ports.
If you connect to a remote server everything is fine, but trying to connect to a remote client on port 3128 allocated by the router might sometimes block and this is not a user issue as much as it is ISP/Firewall.
It may not be much related to NAT but it affects it much and it is not mentioned so i just wanted to post it.

3128 AFAIK is a common proxy port. Some ISP's might block this on their routers.

You are using a common trojan port.

Use a different port.