These issues are naturally compounded when heterogeneous CPUs are used in a network with messages being passed among them. If the implementor of the message-passing scheme doesn't decide up front what byte order will be used, then some form of identification needs to be done so that a machine with a different byte ordering can receive and correctly decode a message from another machine. This problem has been solved with protocols like TCP/IP, where a defined network byte order is always adhered to, even between homogeneous machines whose byte order differs from the network byte order.