Abstract: In an asynchronous message queuing network, a data processing method of finding a lost message includes the steps of: sending a first message from an originating data processing unit to an intermediate data processing unit, the message including an indication that the message is traceable; sending a tracer message from an originating data processing unit to an intermediate data processing unit, the tracer message identifying the first message as a lost message which the originating data processing unit would like to find; at the intermediate data processing unit, upon receiving the tracer message, checking to determine whether the first message exists within the intermediate data processing unit, and sending a reply message back to the originating unit if the first message is found within the intermediate data processing unit; and at the intermediate data processing unit, if the first message is not found within the intermediate data processing unit, determining whether the first message has passed through th

Abstract: A data communications apparatus connected to a network through which datagrams flow from the data communications apparatus to at least one other data communications apparatus also connected to the network, the apparatus having: a means for receiving data which is to be transmitted over the network, such data being broken up into data records; and a means for packing the data records into datagrams for transmission over the network, including a means for assigning data records to datagrams; wherein the means for packing takes the data records out of sequential order when assigning data records to datagrams.