directplay problem

I had a situation, when the multiplayer game already setup the connection, the host send the game data to the client(player), it receive some what immediately, the speed is acceptable, but when the client(player) send the data to the host, the host receive the data very slow, like 7 seconds delay, on my game I use the peer-to-peer network. Both the host and player use the same function send to I generate. is there any suggestion for this? thanks,