Patent ID: 7571252

Claim:
A computer system, comprising: a first client device; a second client device; a network interconnecting the first and second client devices; wherein the first client device is configured to initiate a first coherency transaction by sending a packet to the second client device via the network; wherein the first coherency transaction is associated with a transaction ID including a subset ID and a packet characteristic ID, wherein the subset ID identifies a unique one of a plurality of outstanding transactions within a class of the first coherency transaction at each of the first and second client devices; wherein the first client device is configured to include the subset ID within and to exclude the packet characteristic ID from the packet sent to the second client device; wherein the second client device is configured to respond to the first coherency transaction by generating the packet characteristic ID dependent upon information encoded in the packet sent by the first client device and to send a responsive packet to the first client device via the network, wherein the responsive packet comprises the transaction ID including the subset ID and the packet characteristic ID; and wherein the first client device is configured to associate the responsive packet with the first coherency transaction based on the transaction ID including the subset ID and the packet characteristic ID.