Obviousness

Obviousness Analysis of U.S. Patent 8,589,587 Under 35 U.S.C. § 103

This analysis identifies combinations of prior art that would render the independent claims of U.S. Patent 8,589,587 obvious to a person having ordinary skill in the art (POSITA) at the time of the invention (priority date: May 11, 2007). The core inventive concept across the independent claims (Claims 1, 6, and 12) is the moderation of application payload data arrival notifications by an intelligent network adaptor, where this moderation is based on the adaptor processing transport header data (specifically, urgent (URG) and push (PSH) indicators) within a stateful connection to indicate application-level events.

Independent Claims 1, 6, and 12: Key Elements

The independent claims describe a system, method, and intelligent network adaptor with the following key features:

1. Intelligent Network Adaptor (INA): Couples a host to a network, the host running an application to receive data.
2. Transport Protocol Processing: The INA performs transport protocol processing for a stateful connection (e.g., TCP/IP).
3. Application Data Copying/Placement: The INA copies/places application payload data from itself to host memory (application buffers or OS buffers).
4. Notification Rate Moderation: The INA moderates the rate of providing application payload data arrival notifications to the host, without terminating the stateful connection.
5. Trigger for Moderation: This moderation is based on the INA determining (by processing transport header data) that an incoming packet contains "useful application level notifications at the transport layer indicative of events occurring at the application layer."
6. Specific Notifications: These application level notifications at the transport layer include at least one of an urgent indicator (URG) or a push indicator (PSH).

Combination of Prior Art References

A combination of the following prior art references would render claims 1, 6, and 12 obvious:

• Primary Reference: U.S. Patent 6,757,746 B2 to Alacritech, Inc. (hereinafter "Alacritech '746").
• Secondary Reference: U.S. Patent Application Publication 2007/0064737 A1 to Emulex Design & Manufacturing Corporation (hereinafter "Emulex '737").
• General Knowledge: A person having ordinary skill in the art's understanding of standard TCP/IP protocol behavior and the meaning of TCP control flags.

Alacritech '746: Intelligent Network Adaptor with Direct Data Placement

Alacritech '746 teaches an intelligent network interface device (equivalent to an intelligent network adaptor) that can write network data directly into host memory without headers, thereby performing direct data placement (DDP) or "zero-copy" operations. This device is configured to obtain a destination address in host memory for this direct write. The patent broadly covers:

• An intelligent network adaptor coupled to a host and a network.
• The adaptor performing protocol processing to extract application payload data.
• Copying/placing application data from the adaptor to host memory (e.g., application buffers).
• This typically occurs within the context of connection-oriented protocols like TCP/IP, where such offload engines (TOEs) were known to process stateful connections.

Alacritech '746 therefore establishes elements 1, 2, and 3 of the independent claims.

Emulex '737: Receive Coalescing for Notification Moderation

Emulex '737 teaches a network interface controller (NIC), which is an intelligent network adaptor, configured to perform "receive coalescing." Receive coalescing is a technique specifically designed to moderate the rate of providing notifications (e.g., interrupts) to the host by grouping multiple received packets or completion events before generating a single notification. This directly addresses element 4 of the independent claims: "moderating a rate of providing application payload data arrival notifications to the host." Emulex '737 was published on March 22, 2007, prior to the priority date of US8589587 (May 11, 2007), making it valid prior art.

General Knowledge of TCP/IP Protocol and Flags

A POSITA at the time of the invention would be fully aware of the Transmission Control Protocol (TCP) and its header control flags, including the Urgent (URG) pointer flag and the Push (PSH) flag, as defined in RFCs (Request for Comments) and commonly implemented in networking stacks. The patent US8589587 itself acknowledges these flags, stating: "TCP may carry signaling that may loosely be considered application level signaling in the TCP header control flags, such as the FIN, URG and PSH flags. The FIN flag indicates that the sender/peer has finished sending data. The URG flag indicates that the Urgent pointer is set (indicating that the payload data should reach the host quickly). The PSH flag indicates that a segment should be passed to the application as soon as possible."

The meaning and intent of these flags are to convey specific requirements for data handling to the receiving application. The URG flag indicates that the data should be processed with urgency, and the PSH flag indicates that buffered data should be immediately sent to the application.

Motivation to Combine

A person having ordinary skill in the art would have been motivated to combine the teachings of Alacritech '746 with Emulex '737 and general TCP/IP knowledge for the following reasons:

The background of US8589587 highlights critical challenges in high-speed network communications, including a "high packet arrival rate, which implies a high associated interrupt rate," significant "memory bandwidth resources to copy application payload data," and the need for "low communication latency".

1. Reducing Host Overhead and Improving Efficiency: Alacritech '746 provides a solution to the memory bandwidth challenge by enabling direct data placement, avoiding costly memory copies from OS buffers to application buffers. However, even with direct data placement, a high rate of notifications (e.g., interrupts) from the network adaptor to the host still places a significant burden on the host processor. Emulex '737 directly addresses this by teaching receive coalescing to moderate notification rates, thereby reducing the host CPU's interrupt processing load. A POSITA, aiming to further optimize host system performance, would naturally combine these two approaches: use direct data placement for efficient data movement and coalescing for efficient notification handling.

2. Maintaining Low Latency for Critical Data: While coalescing reduces overall notification rates, it might introduce latency for certain data if notifications are unduly delayed. The purpose of TCP's URG and PSH flags is specifically to signal that particular data segments require urgent or immediate attention by the application. A POSITA integrating notification moderation into an intelligent network adaptor (which already performs TCP protocol processing as described in Alacritech '746) would find it obvious to use these standard TCP flags as triggers to override general coalescing logic. That is, if a packet arrives with the URG or PSH flag set, the adaptor should generate an immediate notification to the host, even if other coalescing conditions (e.g., timer not expired, buffer not full) are not met. This ensures that application-level urgency is respected, preventing undue delays for critical data, while still moderating notifications for less urgent data. This directly addresses the patent's stated goal of achieving "low communication latency with reduced demands on host processing and memory resources".

3. No Termination of Stateful Connection: The act of processing TCP headers and moderating notifications within an ongoing TCP session is inherent to the function of a TCP offload engine and receive coalescing. Neither direct data placement nor notification coalescing implies terminating the stateful connection; rather, they are mechanisms to manage data flow within an active connection more efficiently. Therefore, providing notifications "without terminating the stateful connection" is a natural outcome of applying these techniques to standard TCP/IP communications.

Conclusion

Based on the foregoing, a POSITA would have been motivated to combine the direct data placement capabilities of an intelligent network adaptor (as taught by Alacritech '746) with the notification moderation techniques of receive coalescing (as taught by Emulex '737). Furthermore, in such a combined system performing TCP/IP processing, it would be an obvious design choice to leverage the well-known semantic meaning of TCP URG and PSH flags within the transport header data to intelligently trigger immediate notifications, ensuring timely delivery of critical application data while still reducing overall host interrupt load. This combination directly addresses the problems of high host processing burden and latency in high-speed networks, which were known in the art and explicitly articulated in the background of US8589587. Therefore, independent claims 1, 6, and 12 would have been obvious under 35 U.S.C. § 103.