Patent ID: 7328273

Claim:
A protocol duplicating configuration for making identical an order of reception and contents of packets on first and second computers which are connected to a network, have shared memories forming a same address space, and make up a duplicated computer system for rackets of specified communications, characterized by having on each of the first and second computers: queue storing means for storing packets to be processed in order of being processed; protocol processing means that is executed in response to reception of packets from the network; temporary queue holding means for temporarily storing the packets having been processed by the protocol processing means in a queue; and virtual queue storing means for storing packets of target communication for the protocol duplication in a queue; wherein the protocol processing means has packet taking-in means which takes in packets one by one from the queue storing means and determines whether each packet taken in is a packet of target communication for the protocol duplication, communication processing means for performing protocol processing on the packet, and packet output means for outputting the packet having been processed by the protocol processing means to the temporary queue storing means; and wherein the protocol processing means on the second computer takes in the packets stored in the queue storing means on the second computer one by one by means of the packet taking-in means and determines whether each packet taken in is a packet of target communication for the protocol duplication, and if the packet is a target packet, discards the packet and passes the packet at the head of the queue in the virtual queue storing means on the second computer to the communication processing means.