Patent ID: 6724762
Filing Date: 2004-04-20
Classification: G06F,H04L

Abstract:
In a system area network (SAN) interconnecting a requestor and a responder, a sub-system for managing ordered transactions requiring strict ordering of packet reception and remote direct memory access that allow out-of-order receipt of packets, the sub-system comprising:a first network interface card (NIC) interconnecting the requestor and the SAN for transferring a request packet from the requestor to the responder, the first NIC being configured to locally maintain a request sequence number for the request packet and to provide the request packet with the request sequence number and a packet order field that is set to a first value or a second value, wherein the first value specifies an ordered transaction requiring packets to be received in order in which case the request sequence number is incremented for each transferred request packet, and wherein the second value specifies an unordered transaction allowing packets to be received out-of-order in which case the request sequence number remains unchanged with transmission of request packets; and a second NIC interconnecting the responder to the SAN for receiving the request packet and transferring a response packet, the second NIC being configured to locally maintain a response sequence number that is incremented subsequent to sending the response packet if the packet order field of the corresponding received request packet is set to the first value and is not incremented if the packet order field is set to the second value.