Data transmission rate


I have a problem with receiving and sending data. I have a packet, which transmitted from client to server and from server to clients on every FixedUpdateNetwork tick (for example, 30 ticks per second). And i found, that client send about 30 packets per second, but server receive only about 12-15 packets per second. There is no packet loss, because remainig packets have received on the next seconds. To send packets to server i use SendReliableDataToServer method. How can i make too receive and send the same number of packets?