This is Thai volleyball. The difference is that it uses a lightweight bamboo ball and you cant use your hands - sorta like a cross between soccer and volleyball.
I met these guys in this park in Bangkok. I spoke with one of them and he says they have been playing almost every day for the last 10 years.
Keep an eye on the guy wearing the red scarf on his head. He does these crazy backflips to hit the ball over, and misses only 5% of the time. He is so good that the other players on his team only hit the ball to him to win.