When you use MyChat direct file transfer in a local network between two users, the recipient performs as the server and the sender is the client.

 

They connect via FTP protocol using two TCP ports: for transferring commands and exchanging binary data.

 

Fixed

If users physically work on different computers, you can use two fixed ports. It's easier from the administrator perspective as he can configure local anti-viruses and firewalls. You can configure the local firewall (Brandmauer) in such a way that it lets packages go through ports you choose. By default, these are TCP ports10000 and 10001.

 

Random, from the range

If you run MyChat in a terminal session on one Windows server with many other clients, you need to set these settings. Various clients won't interfere with each other when exchanging files occupying the same ports. The ports for file transferring selected from a specified range.

 

For example, if ports 10000 and 10001 are occupied, MyChat Client "tries" 10002 and 10003, etc., until it finds a free pair. The process of selecting ports is written to the client protocol.