Patent ID: 7360029

Claim:
A node for use in a multi-node system, the node comprising: a plurality of active devices; an interface to an inter-node network coupling nodes in the multi-node system; an address network configured to convey address packets between the interface and the plurality of active devices; and a data network configured to convey data packets between the interface and the plurality of active devices, wherein the address network and the data network are separate networks each including a respective plurality of communication links; wherein an active device of the plurality of active devices is configured to send an address packet on the address network to initiate a transaction to gain an access right to a coherency unit; wherein in response to the address packet, the interface is configured to send data, via the data network, corresponding to the coherency unit to the active device if no other active device in the node has an ownership responsibility for the coherency unit and the coherency unit is in a modified global access state in the node; and wherein the active device is configured to gain an ownership responsibility for the coherency unit in response to receiving the address packet, wherein the interface is configured to send a proxy address packet on the address network in response to receiving the request from the another node, wherein the active device is configured to store a promise corresponding to the proxy address packet in a promise array included in the active device in response to receiving the proxy address packet while having the ownership responsibility for the coherency unit, but not having the data corresponding to the coherency unit; wherein the promise comprises information that identifies a particular data packet that needs to be forwarded, and the destination to which the data packet must be forwarded.