US Patent 7620694 Early issue of transaction ID

Early issue of transaction ID is disclosed. An apparatus comprising decoder to generate a first node ID indicative of the destination of a cache transaction from a caching agent, a transaction ID allocation logic coupled to and operating in parallel to the decoder to select a transaction ID (TID) for the transaction based on the first node ID, a packet creation unit to create a packet that includes the transaction, the first node ID, the TID and a second node ID corresponding to the requestor.