Network client send more than server

Hello, i use unity's network.

I try to optimize bandwidth. In moment action where weapon fx guihit ... are triggered my application can meet 20KByte (sent) and 10 KByte (recv).

In this test the client just send his position. And the server trigger lot of RPCs.

But the most impressive is that this client is not a server.

My point of view are: - Debug recv/sent byte display through network are buggy, maybe because client and server are on the same machine. - When i enable network debugging i can see that client "relay RPC" and i dont understand what it means. Maybe relay means to send back to the server? but why...

Thank you!