Format of datagrams : bytes 0 & 1 : ffff for discovery packet, 0000 for everything else byte 2 : sequence number (high part) byte 3 : sequence number (low part) byte 4 : 2 = ask question or send info, 1 = answer or ACK, 0 = retransmit request byte 5 : direction, 1 = server to phone, 2 = phone to server arguments