why say in status "playing in a private match" and i cant join

[JulianCh]

when i try to playing with my friend in the some map, i do double click in him name and say "joining the game session" but never joining and in the status say"playing in a private game"
HELP

[HannesC]

Does he have UPnP enabled? If he has it disabled, that won't work, not all routers support it. He's gotta port forward manually, follow this guide.