Direct Connection Matchmaking is designed to allow direct connection matchmaking through the use of UPnP, and a MySQL based matchmaking server.

Advantages:

• Establishes a direct connection if the host's router supports UPnP (The vast majority do).
• Direct connection bypasses Unity's relay servers, which saves you money and reduces latency.
• Only a MySQL server is needed to facilitate matchmaking, which is cheap / free compared to other server / database types.
• If the host's router doesn't support UPnP, the Unity relay service will be automatically used.
• MySQL database PHP code is secure and protected against SQL injection. MD5 hashing is used for transmitted data. Passwords for servers are never sent or stored in plain text.
• Documented API and instruction manual.
• Tested on Windows standalone and Android builds. It should work on other build platforms except WebGL.

How it works:

1. The host searches for a connected UPnP compatible device (router) when starting a match.
2. If found, a suitable port is determined and opened using UPnP.
3. The data needed for clients to join the match is sent to the MySQL server and listed.
4. Clients query the MySQL server for a suitable match and join through direct connection.
5. If a UPnP compatible device is not found, then a match will be created using Unity’s relay servers.
6. Both types of matches can be joined.

What is needed:

• A server running MySQL, and with PHP access.