by visan.ovidiu:

Right now RemoteAddr() method can be called to get the RPC client's address only on
net.Conn when the client dials to server, but suppose that your server has multiple
clients connected and each of this clients are calling an RPC exported method. Is there
a way to implement a method to get the caller's remote address from inside the RPC
method?

func (t *Type) Method(args *Args, reply *string) error {
    //something like
        *reply = Caller.RemoteAddr().String()
        // who called the method now?
    return nil
}