Patent Grant
8589587
This application is related to the following U.S. Non-Provisional applications: application Ser. No. 11/747,650, By: Dimitrios Michaelidis, Wael Noureddine, Felix Marti and Asgeir Eiriksson, Entitled “INTELLIGENT NETWORK ADAPTOR WITH ADAPTIVE DIRECT DATA PLACEMENT SCHEME”; application Ser. No. 11/747,673, By: Dimitrios Michaelidis, Wael Noureddine, Felix Marti and Asgeir Eiriksson, Entitled “INTELLIGENT NETWORK ADAPTOR WITH END-TO-END FLOW CONTROL”; and, application Ser. No. 11/747,793, By: Dimitrios Michaelidis, Wael Noureddine, Felix Marti and Asgeir Eiriksson, Entitled “INTELLIGENT NETWORK ADAPTOR WITH DDP OF OUT-OF-ORDER SEGMENTS”; all of which are filed concurrently herewith and are incorporated by reference herein in their entirety for all purposes.
The present invention relates to efficient receive data communication using an intelligent network adaptor.
High speed communications over packet-based networks can place a heavy burden on end-host resources.
A host may typically be connected to a network using at least one network adaptor. The network adaptor receives packets from the network that are destined for the host. The network adaptor causes the packets to be placed in host memory buffers associated with the operating system. When one or more packets have been placed, the adaptor notifies the host processor of this event, typically using an interrupt. The packets are then processed by the host operating system, including delivering application payload data of the packets from the operating system buffers to buffers of a destination application corresponding to the packets.
Each application data bearing packet received from the network includes the application data, encapsulated within a stack of headers according to a network communication stack. For example, the network communication may be via TCP/IP over Ethernet. In this case, the TCP/IP stack encapsulates application data in a TCP header, and the TCP encapsulated data are encapsulated in an IP header. The TCP/IP encapsulated data are encapsulated in a header according to a local area network technology protocol, such as Ethernet.
In the high-speed communications environment, there are several challenges for end-host resources. One challenge is the high packet arrival rate, which implies a high associated interrupt rate as the host is notified of the arrival of each packet. Another challenge is associated with the memory bandwidth resources to copy application payload data from the operating system buffers to application buffers. Yet another challenge is to achieve low communication latency between the network and the host via the network adaptor, such that application payload received from the network by the network adaptor is provided in a relatively expedient manner to the application.
The present invention in some aspects may be directed to one or more of these challenges identified above to result in high speed and low latency communication with reduced demands on host processing and memory resources.
The challenges of high-speed communications have led to enhancements to network adaptor capabilities, resulting in so-called “Intelligent Network Adaptors” that, for example, offload some or all network communication protocol processing. In addition, direct data placement (DDP) is known. It refers to the capability of some intelligent network adaptors to process network packets arriving from the network and place payload data contained within the network packets directly into pre-determined locations in host memory.
An intelligent network adaptor couples a host to a network. The host executes an application configured to receive data packets including application data from a peer via the network and the intelligent network adaptor using a stateful connection between the host and the peer according to a connection-oriented transport protocol. The intelligent network adaptor performs transport protocol processing of the connection with respect to the received packets. Application data of the received packets, received from the peer via the stateful connection, is copied from memory of the intelligent network adaptor to host memory. Data receive notifications are provided from the intelligent network adaptor to the host based at least in part on application level notifications, in the transport protocol signaling, in the received packets.
The inventors have realized that a destination in a host for application data of payload packets protocol processed by a network adaptor, may be selected, and such selection may contribute to improved overall performance of communication of application payload data from the network, via the network adaptor, to the application executing in the host.
Generally speaking, network speed increases have not been accompanied by a proportional increase in packet size. As mentioned in the Background, in a high-speed network, the host processor (or processors) may see a high packet arrival rate and a resulting high notification (e.g., interrupt) rate. Handling the notifications can divert a significant part of the host resources away from application processing. Interrupt rate moderation schemes are known, but have limited effectiveness and can introduce delays that may increase communication latency.
Before describing an example of how a payload data destination in the host may be selected, we first discuss more particularly what may be considered a “packet” and how packets may be processed according to one or more protocols. A packet is typically constructed to include application payload data and a sequence of headers (at least one header). Each header may be encapsulated in a lower layer header. The lowest layer is typically called the Media Access Control (MAC) layer (e.g., under a generalized ISO 7-layer model), though other identifiers may be used. A MAC packet is usually called a frame, and includes a MAC header, payload bytes and a trailer. An example MAC layer protocol is Ethernet. An upper layer protocol packet is typically encapsulated in a MAC frame. In the context of the Internet, a common protocol encapsulated in a MAC frame is the Internet Protocol (IP). Another common protocol encapsulated in the MAC frame is the Address Resolution Protocol (ARP). A higher layer (transport layer) packet, such as a TCP or a UDP packet, is typically encapsulated in an IP packet.
Processing of packets received from the network includes protocol processing of the packets based at least in part on the sequence of headers. Connection oriented protocols typically maintain state to be used in protocol processing at the communicating endpoints. Protocol processing is typically carried out before application payload is delivered to the appropriate destination application or applications. Protocol processing in the context of high-speed networks may use significant resources. It is now common for network adaptors to implement intelligence for the support of host processing, including to partly or completely offload protocol processing. Such adaptors are sometimes referred to as intelligent network adaptors.
A highly desirable capability of an intelligent network adaptor is the capability to place application data directly into pre-determined memory locations. For example, these locations may be in host memory or in memory of another adaptor. Direct data placement can significantly reduce the memory bandwidth used for delivery of data received via network communication. In particular, direct data placement may allow placing data directly into application buffers from the intelligent network adaptor, thereby avoiding the copying of packet payload from operating system network buffers to application buffers. This capability is typically referred to as “zero-copy.” In addition to saving CPU cycles, the omission of the data copy also saves on application end-to-end latency, as “store-and-forward” memory copies introduce a delay in the end-to-end communication of the application data.
Broadly speaking, applications may differ in their interaction with the host operating system's network protocol processing stack interface. This difference may in part be dependent on the operating system that implements the network protocol processing stack software. To achieve zero-copy data transfer to application buffers, an application typically provides a destination buffer into which the adaptor can directly place application payload data of packets received from the network. Conceptually, an application buffer may include one or a chain of memory locations, each described by a memory address and a length. Typically, it is a network adaptor device driver of the host operating system that handles mapping between the application buffer and descriptors of the chain of memory locations.
Benefits of zero-copy may depend on the size of the buffer provided by the application, and the expediency that an application wishes to get data. For example, there may be a tradeoff between the cost of copying packet payload (e.g., from an operating system buffer to an application buffer) and overhead cost associated with mapping an application buffer into a chain of memory descriptors (for zero copy). The tradeoff involves latency, i.e. having the data wait in the adaptor memory while the mapping is being created, rather than receiving packets through the operating system buffers, while simultaneously setting up memory maps to enable the zero-copy receive of data directly to the application buffers. The mapping typically involves communicating with the host operating system to reserve (referred to as pinning) memory in the host machine that is to receive the zero-copy application data.
The mapping process further includes communicating the mapping to the network adaptor. A standard Ethernet frame carries 1500 B of data, and the mapping is created when the first frame arrives, and if the overall transfer size is only on the order of say 8000 B, and data is being received for a single connection than it is likely that the overhead of zero-copy will be greater than receiving the packets through operating system buffers. When multiple connections are receiving data simultaneously then zero-copy is more efficient even for smaller transfer sizes, because while the mapping is being created for one connection, it is possible that data is being received with zero-copy mechanism for other connections.
Benefits of direct data placement can depend on the application's ability to post buffers and the traffic pattern. Direct data placement to an application buffer is possible if the application has posted a buffer when the application data arrives from the wire and is to be written from the network adaptor to the host. Some application programming interfaces, such as the widely adopted synchronous sockets interface, allow the application to post only one buffer. In such a case, once that buffer is completed and returned to the application, additional incoming application data for the input request can not be directly placed. Thus, for example, the additional incoming data can be stored in memory of the network adaptor and later directly placed when the application posts the next read, or the incoming application data can be placed (e.g., by DMA) to an operating system buffer. In the latter case, when an application buffer is available (e.g., the application posts another buffer), the application data would then be copied from the operating system buffer to the application buffer.
In general, the amount of data that is placed in an operating system buffer is limited if an application buffer becomes available in a timely manner. In addition, copying from the operating system buffer to the application buffer can be done in parallel with the network adaptor operating to cause additional incoming application data to be placed into the same application buffer (e.g., if the application buffer is posted by an application only after the network adaptor already receives application data for that application). Thus, for example, the application data copied from the operating system buffer to the application buffer may be placed at the beginning of the application buffer while the additional incoming application data is placed into the same application buffer at an offset, to account for the data that was previously placed into the operating system buffer.
An intelligent network adaptor may be provided to offload the processing of the stack of headers of the packets. Furthermore, the intelligent network adaptor may be configured so as to reduce the notification rate according to the transport protocol, with minimal or no application level delays being introduced.
In one example, the copy vs. zero-copy decision may be addressed (e.g., in a driver program that interoperates with or is part of the operating system of the host) by using an adaptive scheme that selectively performs one or the other depending on various criteria. For example, a decision may be based in part on, or indirectly result from, the size of the application buffer. This scheme may be transparent to applications so as to not require any application modification or awareness. We refer to this scheme as the “adaptive copy avoidance” scheme. In addition, data may be directly transferred to application space. Applications can make use of this method for highly efficient, flexible, high-speed, very low latency communication. We refer to this as the “memory mapped receive” scheme.
For the purpose of illustration in this description, we refer to applications that use the Transmission Control Protocol (TCP) to communicate over an Internet Protocol (IP) network. The description herein serves the purpose of illustrating the process of application data delivery over a network, and it is not intended to be construed as limiting the applicability of the described methods and systems to this particular described context.
TCP provides a reliable data stream delivery service. TCP is a connection-oriented protocol according to which a stateful association is established between two communicating end-points such as between an application, executing in a host, and a peer located across a network from the host. In this context, each packet may include a 4-tuple designating a destination IP address, a source IP address, a destination TCP port number and a source TCP port number, to uniquely identify a connection. An intelligent network adaptor configured to offload the processing of the TCP/IP protocol stack from a host is typically referred to as a TCP Offload Engine (TOE).
In contrast to the conventional payload delivery described with respect to
The adaptor may moderate the rate of providing payload data arrival notifications by, for example, only generating a payload arrival notification to the host processor 312 if the incoming packet is determined by the adaptor to contain useful application level notifications. Whether an incoming packet contains useful application level notifications may be determined, for example, by processing the application payload in the intelligent network adaptor, from signaling according to the transport protocol in the protocol header, or from the level of data in an application level buffer (e.g., the application level buffer is full or nearly full). With respect to signaling according to the transport protocol, in a TCP/IP context, 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.
In this example, the memory location for direct placement of application payload data may be dependent on the adaptive copy avoidance scheme. According to the scheme, if zero-copy is to be used, the application buffer descriptors have been communicated to the adaptor from the host and, based on this, the intelligent network adaptor operates to directly place payload in the application buffer according to the descriptors. Otherwise, application buffer descriptors have not been communicated to the adaptor, and application payload is placed in a memory location not corresponding to an application buffer, such as, for example, in a memory location corresponding to an operating system network adaptor buffer, for subsequent copying into an application buffer.
We now describe a specific example of data delivery according to an example of the adaptive copy avoidance scheme, with reference to
We now particularly discuss operation of the host, with respect to the application, affecting whether buffer descriptors corresponding to application buffer memory are communicated to the intelligent network adaptor (or the intelligent network adaptor is otherwise configured for zero copy with respect to the application). For example, an application may perform input/output (I/O) data transfer operations by presenting a memory buffer to the operating system 307 to/from which data transfer is to occur. One criterion for deciding whether to configure the intelligent network adaptor for performing zero-copy for a data receive I/O operation may be the buffer size passed by the application relative to the size of a copy source buffer that would otherwise be used. As mentioned earlier, if the size of the application buffer is relatively small, the overhead involved in setting up a zero-copy operation can become a significant portion of the operation.
In this case, a copy operation may be more advantageous, particularly when the source buffer of the copy operation (i.e., if the copy operation is to be used) is larger than the size of the application buffer. Then, it may result that data transfer occurs from the adaptor to a copy source buffer in the host memory. The copy source buffer is typically (but need not necessarily be) in memory controlled by the operating system 307. The data in the copy source buffer (written from the adaptor) can be subsequently copied to the application buffer 309. If the size of the application buffer is relatively larger, the I/O operation can be expected to be relatively longer, and it can be worthwhile to expend the overhead to set up a zero copy operation based on the expected efficiencies gained in carrying out the zero copy operation.
Another criterion for determining whether to perform zero copy may be whether the application buffer sizes are large enough relative to the amount of application data being received for zero copy to be “useful” such as, for example, to reduce data transfer overhead (in contrast to increasing zero copy setup overhead). When the application buffer sizes are “sufficiently large” for zero-copy to be useful (for example, there is enough room in the application buffer to accommodate all the data of a particular transfer from the intelligent network adaptor to the application), an indication of the memory locations corresponding to the application buffer are communicated to the intelligent network adaptor. For example, this communication of memory location indications may be initiated by operating system drivers associated with the intelligent network adaptor. The intelligent network adaptor can then place incoming data directly into the application buffer based on the indications of memory locations.
In some cases, after requesting an input (receive, read) operation, an application waits for the operation to complete and then performs some processing on the received data before proceeding to request another receive operation. This is typically referred to as “synchronous I/O”. Data that arrives during the time the application has no receive request in place may be saved in some memory—either in memory of the intelligent network adaptor or in host memory (e.g., in memory controlled by the operating system). In this case, the operating system buffer described above (the copy source buffer) can be used to save the received data. This helps minimize idle times and delays and allows for a network adaptor design with less memory and less likelihood to need to drop received packets.
When an application makes a receive request and the operating system buffer contains saved data, the data may be copied from the operating system buffer to the application buffer. Furthermore, if the application buffer is large enough to hold all the saved data, the application buffer information may be communicated to the intelligent adaptor. Then, the adaptor can start placing additional received data of the request in the application buffer at an offset based on the data previously placed in the operating system buffer. The operating system can independently and simultaneously copy the saved data into the application buffer. This approach has an advantage that latency of the data transfer may be minimized in that data may be copied to the application buffers via the operating system buffers as soon as the data is requested by the application and, simultaneously, the operating system interoperates with the adaptor to cause the adaptor to be configured with the mapping information so that subsequent data can be placed directly in the application buffers with zero-copy.
Some applications may be capable of placing multiple receive requests. Such applications can process data received corresponding to one request (and, for example, in one request buffer) while, simultaneously, data received corresponding to another request can be placed into another buffer. This is sometimes referred to as “asynchronous I/O”. Such applications may be capable of ensuring that at least one receive request is in place at all times, and therefore may operate without needing an operating system buffer to handle the “no receive request” case as described above. When the adaptor completes transfer to one application buffer, the host system is notified, and subsequent data can be placed in another application buffer (such as in the following application buffer in sequence). A driver associated with the intelligent network adaptor may control where incoming data is placed. For example, the adaptor may simply pin and map the application buffer memory for direct memory access of application payload data from the intelligent network adaptor to the host.
In accordance with another aspect, an intelligent reduction in notification rate regarding data received from the network and provided from the intelligent network adaptor to an application buffer memory of the host or a copy source buffer of the host may improve host system performance without affecting (or with minimal effect on) communication latency. The notification rate for the data transfer process to the copy source buffer may be moderated by the intelligent network adaptor to be on a greater than per-packet basis to reduce host system processing load to respond to the notifications. Accordingly, data transfer for a connection from the intelligent network adaptor to the host system may be performed “silently” without any data transfer notification to the host system, for example, until such a notification is deemed useful. Useful notifications may correspond to events occurring at the application layer, determined by the intelligent network adapter through processing the application layer information. Other useful notifications may correspond, for example, to events occurring at a layer lower than the application layer, such as at the transport layer. For example, useful data notifications may correspond to the receipt and detection, by the intelligent network adaptor from the network, of a special TCP control flag, such as the PSH flag, the URG flag, or the FIN flag for the connection. A different type of notification may be sent when a non-graceful teardown of the connection occurs, such as receipt of a valid RST flag or other abortive events.
It is useful in some situations to provide data transfer notifications from the intelligent network adaptor to the host on the basis of elapsed time, such as on a periodic basis, or when the memory buffer in use is filled up, or when a timer elapses since the last data had been silently placed. These measures help to allow the application processing to proceed at a steady rate, and forward progress when the last data has arrived. The first of these (elapsed time, such as periodic basis) is useful in the cases where the data is arriving slowly, as it can assist the application in getting an opportunity to process the data at a steady rate with acceptable latency. The second (when the memory buffer in use is filled up) assists the application in processing at a steady rate and/or the application can process data while new data is arriving (pipelining). The last of these (timer elapses since the last data had been silently placed) applied at least to the “end of data” case, i.e. no more data is forthcoming and a timer ensures that the application makes forward progress in processing the application data.
A flow control scheme can be established for use with direct data placement functionality (whether in accordance with the adaptive copy scheme discussed above or otherwise). In an example implementation, a number of data credits are provided to the intelligent network adaptor. The credits may correspond to an amount of data received. When the intelligent network adaptor buffers the data itself (e.g., because the data cannot be delivered on-the-fly to the host for some reason), the receive window being advertised to the peer is shortened (e.g., by the number of bytes that are buffered by the adaptor). When the data is eventually placed on the host, then the advertised receive window is lengthened (e.g., by the number of bytes that are placed). If the data placed on the host cannot be directly placed to an application buffer (e.g., is held in a “common pool” of buffers), then the receive window is accordingly shortened, and when the data is eventually delivered to the application, the receive window is again lengthened.
Conversely, when the application consumes data and application buffer becomes available, the credits are returned to the intelligent network adaptor, and its credit count incremented accordingly. If the TCP window flow control is made dependent on this flow control scheme, such as by basing the TCP window size on the number of credits available to the intelligent network adaptor, it is possible to perform end-to-end flow control with the application as terminus, as opposed to with the intelligent network adaptor or operating system buffers as terminus. One benefit of this arrangement may be that less memory may be used in the intelligent network adaptor, since flow control is based on the available memory in the host for the application and is not based on (or, at least, is not based completely on) the available memory in the intelligent network adaptor.
We now move to discuss an example of a method for managing the transfer to application memory space. The method allows high bandwidth and low latency, at low host system load. It may allow applications executing on the host to perform random access to the received data in application memory.
Referring to
The intelligent network adaptor may place received out-of-order data directly in the buffer 409, and therefore perform data re-assembly in the buffer 409 itself, e.g., if the data is received out-of-order in accordance with an applicable transport protocol for the connection. In this case the adaptor keeps track of which data has already been placed in the application buffer, and which data is still to be delivered, and notifies the application when all the data has been placed, or in case of a delivery timer expiring, how much of the in-order data at the start of the buffer has been delivered. Alternatively, out-of-order data re-assembly may be performed in a different memory location (e.g., in adaptor memory), with only in-order data being placed in the buffer 409. In either case, the progress of the receive operation may be indicated in terms of the memory address containing the latest byte received in-order. Payload data of at least some of the packets can, after being reordered spatially, be considered to comprise payload data of an equivalent newly-configured packet. In this case, the peer may be provided an acknowledgement of the equivalent newly-configured packet.
A flow control scheme may be used to control the amount of data provided to the host. For the sake of illustration, we now discuss an example of the flow control in more detail. In one example, byte granularity flow control is performed on an end-to-end basis by assigning a total amount of flow control credit equal to the size of the mapped receive memory. As one example, TCP allows up to 1 GB of memory to be used for flow control. An even larger receive memory can be utilized by dividing the receive memory into smaller sized “windows” and proceeding through the windows in sequence, i.e. by moving forward the window into the buffer on which the adaptor is working as the buffer gets filled by the adaptor. In this manner, it is possible to expose 1 GB of memory at a time, and to move through a large memory area by “sliding” the exposed receive window as the data placement progresses.
For each amount of data placed by the adaptor, a corresponding number of units of credit are consumed by the adaptor. The consumed credits are subsequently reflected in the flow control window (by contraction of the window) advertised to the sending peer. Conversely, when the application processes a number of bytes, a corresponding number of units of credits can be returned to the adaptor. The returned credits are subsequently reflected in the flow control window (by expansion of the window) advertised to the sending peer. This scheme allows flow control to be performed directly in terms of receiving application space.
Note that when the placement reaches the end of the mapped memory region, the adaptor can resume placing at the beginning of the memory region, if flow control allows. It is therefore possible to visualize the operation as a ring buffer 413 with a producer pointer 414 corresponding to the latest byte placed in-order by the adaptor, and a consumer pointer 415 corresponding to the last byte consumed by the application. The region 416 in between the consumer pointer and the producer pointer contains received data bytes that can be accessed in random order. The application moves the consumer pointer forward to a new location along the ring when work has been completed on (i.e. consumed) the bytes that fall behind the new pointer location. The number of credits in possession of the adaptor determines the number of bytes that the adaptor is allowed to place on the ring in advance of the producer pointer. A goal of proper flow control is to avoid the producer pointer from crossing over the consumer pointer. In some examples, the producer pointer is not moved every time data is placed. Rather, the producer pointer may be moved when a notification of progress is received, and the notification of progress may be moderated by the intelligent network adaptor to minimize the communication between the intelligent network adaptor and the host Likewise, in returning credits to the intelligent network adaptor, credits may be accumulated and sent to the intelligent network adaptor as a group, which can minimize the number of update messages being communicated.
It is possible to obtain very low latency operation using the memory mapped scheme. In this approach, an application or other host software may interpret a change in the contents of a particular memory location as an indication that new in-order data has become available in the receive buffer. In one example, the change in the contents of the particular memory location may be serialized with respect to the arrived data. In one example, the memory location could be ahead of the last byte of arrived data on the ring buffer, and the data placement by the intelligent network adaptor is guaranteed to be in-order, i.e. without “skips”. By polling such a memory location, the application is informed of the arrival of new data with very low delay.
By intelligently handling transfer of data between an intelligent network adaptor and a host, efficiency and efficacy of peer to host communication can be substantially increased.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4445116 | Grow | Apr 1984 | A |
| 4533996 | Hartung et al. | Aug 1985 | A |
| 5058110 | Beach et al. | Oct 1991 | A |
| 5065397 | Shiobara | Nov 1991 | A |
| 5497476 | Oldfield et al. | Mar 1996 | A |
| 5778189 | Kimura et al. | Jul 1998 | A |
| 5937169 | Connery et al. | Aug 1999 | A |
| 6087581 | Emmer et al. | Jul 2000 | A |
| 6141705 | Anand et al. | Oct 2000 | A |
| 6226680 | Boucher et al. | May 2001 | B1 |
| 6240094 | Schneider | May 2001 | B1 |
| 6247060 | Boucher et al. | Jun 2001 | B1 |
| 6334153 | Boucher et al. | Dec 2001 | B2 |
| 6389479 | Boucher et al. | May 2002 | B1 |
| 6393487 | Boucher et al. | May 2002 | B2 |
| 6397316 | Fesas, Jr. | May 2002 | B2 |
| 6401117 | Narad et al. | Jun 2002 | B1 |
| 6401177 | Koike | Jun 2002 | B1 |
| 6427171 | Craft et al. | Jul 2002 | B1 |
| 6427173 | Boucher et al. | Jul 2002 | B1 |
| 6434620 | Boucher et al. | Aug 2002 | B1 |
| 6460080 | Shah et al. | Oct 2002 | B1 |
| 6463077 | Sato | Oct 2002 | B1 |
| 6470415 | Starr et al. | Oct 2002 | B1 |
| 6510164 | Ramaswamy et al. | Jan 2003 | B1 |
| 6564267 | Lindsay | May 2003 | B1 |
| 6591302 | Boucher et al. | Jul 2003 | B2 |
| 6594268 | Aukia et al. | Jul 2003 | B1 |
| 6625671 | Collette et al. | Sep 2003 | B1 |
| 6658480 | Boucher et al. | Dec 2003 | B2 |
| 6681244 | Cross et al. | Jan 2004 | B1 |
| 6687758 | Craft et al. | Feb 2004 | B2 |
| 6697868 | Craft et al. | Feb 2004 | B2 |
| 6701372 | Yano et al. | Mar 2004 | B2 |
| 6708223 | Wang et al. | Mar 2004 | B1 |
| 6708232 | Obara | Mar 2004 | B2 |
| 6717946 | Hariguchi et al. | Apr 2004 | B1 |
| 6735702 | Yavatkar et al. | May 2004 | B1 |
| 6751665 | Philbrick et al. | Jun 2004 | B2 |
| 6757245 | Kuusinen et al. | Jun 2004 | B1 |
| 6757746 | Boucher et al. | Jun 2004 | B2 |
| 6792502 | Pandya et al. | Sep 2004 | B1 |
| 6798743 | Ma et al. | Sep 2004 | B1 |
| 6807581 | Starr et al. | Oct 2004 | B1 |
| 6813652 | Stadler et al. | Nov 2004 | B2 |
| 6862648 | Yatziv | Mar 2005 | B2 |
| 6907042 | Oguchi et al. | Jun 2005 | B1 |
| 6925055 | Erimli et al. | Aug 2005 | B1 |
| 6938092 | Burns | Aug 2005 | B2 |
| 6941386 | Craft et al. | Sep 2005 | B2 |
| 6965941 | Boucher et al. | Nov 2005 | B2 |
| 6996070 | Starr et al. | Feb 2006 | B2 |
| 7031267 | Krumel | Apr 2006 | B2 |
| 7042898 | Blightman et al. | May 2006 | B2 |
| 7076568 | Philbrick et al. | Jul 2006 | B2 |
| 7089289 | Blackmore et al. | Aug 2006 | B1 |
| 7089326 | Boucher et al. | Aug 2006 | B2 |
| 7093099 | Bodas et al. | Aug 2006 | B2 |
| 7114096 | Freimuth et al. | Sep 2006 | B2 |
| 7124205 | Craft et al. | Oct 2006 | B2 |
| 7133902 | Saha et al. | Nov 2006 | B2 |
| 7133914 | Holbrook | Nov 2006 | B1 |
| 7133940 | Blightman et al. | Nov 2006 | B2 |
| 7136355 | Lin et al. | Nov 2006 | B2 |
| 7155542 | Trainin | Dec 2006 | B2 |
| 7164656 | Foster et al. | Jan 2007 | B2 |
| 7167926 | Boucher et al. | Jan 2007 | B1 |
| 7167927 | Philbrick et al. | Jan 2007 | B2 |
| 7174393 | Boucher et al. | Feb 2007 | B2 |
| 7185266 | Blightman et al. | Feb 2007 | B2 |
| 7191241 | Boucher et al. | Mar 2007 | B2 |
| 7191318 | Tripathy et al. | Mar 2007 | B2 |
| 7239642 | Chinn et al. | Jul 2007 | B1 |
| 7254637 | Pinkerton et al. | Aug 2007 | B2 |
| 7260631 | Johnson et al. | Aug 2007 | B1 |
| 7284047 | Barham et al. | Oct 2007 | B2 |
| 7313623 | Elzur et al. | Dec 2007 | B2 |
| 7320042 | Trainin et al. | Jan 2008 | B2 |
| 7336608 | Sin et al. | Feb 2008 | B2 |
| 7346701 | Elzur et al. | Mar 2008 | B2 |
| 7349337 | Mahdavi | Mar 2008 | B1 |
| 7376147 | Seto et al. | May 2008 | B2 |
| 7408906 | Griswold et al. | Aug 2008 | B2 |
| 7447795 | Naghshineh et al. | Nov 2008 | B2 |
| 7453892 | Buskirk et al. | Nov 2008 | B2 |
| 7457845 | Fan et al. | Nov 2008 | B2 |
| 7460510 | Olivier et al. | Dec 2008 | B2 |
| 7474670 | Nowshadi | Jan 2009 | B2 |
| 7493427 | Freimuth et al. | Feb 2009 | B2 |
| 7533176 | Freimuth et al. | May 2009 | B2 |
| 7583596 | Frink | Sep 2009 | B1 |
| 7594002 | Thorpe et al. | Sep 2009 | B1 |
| 7596634 | Mittal et al. | Sep 2009 | B2 |
| 7609696 | Guygyi et al. | Oct 2009 | B2 |
| 7613813 | Hussain et al. | Nov 2009 | B2 |
| 7616563 | Eiriksson et al. | Nov 2009 | B1 |
| 7656887 | Okuno | Feb 2010 | B2 |
| 7660264 | Eiriksson et al. | Feb 2010 | B1 |
| 7660306 | Eiriksson et al. | Feb 2010 | B1 |
| 7715436 | Eiriksson et al. | May 2010 | B1 |
| 7724658 | Eiriksson et al. | May 2010 | B1 |
| 7735099 | Micalizzi, Jr. | Jun 2010 | B1 |
| 7746780 | Seo | Jun 2010 | B2 |
| 7751316 | Yarlagadda et al. | Jul 2010 | B2 |
| 7760733 | Eiriksson et al. | Jul 2010 | B1 |
| 7813339 | Bar-David et al. | Oct 2010 | B2 |
| 7826350 | Michailidis et al. | Nov 2010 | B1 |
| 7831720 | Noureddine et al. | Nov 2010 | B1 |
| 7831745 | Eiriksson et al. | Nov 2010 | B1 |
| 7844742 | Pope et al. | Nov 2010 | B2 |
| 7869355 | Kodama et al. | Jan 2011 | B2 |
| 7924840 | Eiriksson et al. | Apr 2011 | B1 |
| 7929540 | Elzur et al. | Apr 2011 | B2 |
| 7930349 | Hussain et al. | Apr 2011 | B2 |
| 7945705 | Eiriksson et al. | May 2011 | B1 |
| 8028071 | Mahalingam et al. | Sep 2011 | B1 |
| 8060644 | Michailidis et al. | Nov 2011 | B1 |
| 8139482 | Eiriksson et al. | Mar 2012 | B1 |
| 8155001 | Eiriksson et al. | Apr 2012 | B1 |
| 8213427 | Eiriksson et al. | Jul 2012 | B1 |
| 20010010046 | Muyres et al. | Jul 2001 | A1 |
| 20010021949 | Blightman et al. | Sep 2001 | A1 |
| 20010037406 | Philbrick et al. | Nov 2001 | A1 |
| 20020039366 | Sano | Apr 2002 | A1 |
| 20020101848 | Lee et al. | Aug 2002 | A1 |
| 20020188753 | Tang et al. | Dec 2002 | A1 |
| 20020191622 | Zdan | Dec 2002 | A1 |
| 20030005164 | Trainin | Jan 2003 | A1 |
| 20030018516 | Ayala et al. | Jan 2003 | A1 |
| 20030035436 | Denecheau et al. | Feb 2003 | A1 |
| 20030046330 | Hayes | Mar 2003 | A1 |
| 20030048751 | Han et al. | Mar 2003 | A1 |
| 20030067884 | Abler et al. | Apr 2003 | A1 |
| 20030079033 | Craft et al. | Apr 2003 | A1 |
| 20030158906 | Hayes | Aug 2003 | A1 |
| 20030200284 | Philbrick et al. | Oct 2003 | A1 |
| 20030204631 | Pinkerton et al. | Oct 2003 | A1 |
| 20040003094 | See | Jan 2004 | A1 |
| 20040019689 | Fan | Jan 2004 | A1 |
| 20040028069 | Tindal et al. | Feb 2004 | A1 |
| 20040030745 | Boucher et al. | Feb 2004 | A1 |
| 20040042487 | Ossman | Mar 2004 | A1 |
| 20040047361 | Fan et al. | Mar 2004 | A1 |
| 20040054813 | Boucher et al. | Mar 2004 | A1 |
| 20040062245 | Sharp et al. | Apr 2004 | A1 |
| 20040062246 | Boucher et al. | Apr 2004 | A1 |
| 20040064578 | Boucher et al. | Apr 2004 | A1 |
| 20040064590 | Starr et al. | Apr 2004 | A1 |
| 20040073703 | Boucher et al. | Apr 2004 | A1 |
| 20040078480 | Boucher et al. | Apr 2004 | A1 |
| 20040088262 | Boucher et al. | May 2004 | A1 |
| 20040100952 | Boucher et al. | May 2004 | A1 |
| 20040111535 | Boucher et al. | Jun 2004 | A1 |
| 20040117496 | Mittal et al. | Jun 2004 | A1 |
| 20040117509 | Craft et al. | Jun 2004 | A1 |
| 20040123142 | Dubal et al. | Jun 2004 | A1 |
| 20040158640 | Philbrick et al. | Aug 2004 | A1 |
| 20040165592 | Chen et al. | Aug 2004 | A1 |
| 20040190533 | Modi et al. | Sep 2004 | A1 |
| 20040199808 | Freimuth et al. | Oct 2004 | A1 |
| 20040210320 | Pandya | Oct 2004 | A1 |
| 20040213235 | Marshall et al. | Oct 2004 | A1 |
| 20040240435 | Craft et al. | Dec 2004 | A1 |
| 20050071490 | Craft et al. | Mar 2005 | A1 |
| 20050083850 | Sin et al. | Apr 2005 | A1 |
| 20050083935 | Kounavis et al. | Apr 2005 | A1 |
| 20050102682 | Shah et al. | May 2005 | A1 |
| 20050111483 | Cripe et al. | May 2005 | A1 |
| 20050120037 | Maruyama et al. | Jun 2005 | A1 |
| 20050125195 | Brendel | Jun 2005 | A1 |
| 20050135378 | Rabie et al. | Jun 2005 | A1 |
| 20050135396 | McDaniel et al. | Jun 2005 | A1 |
| 20050135412 | Fan | Jun 2005 | A1 |
| 20050135417 | Fan et al. | Jun 2005 | A1 |
| 20050147126 | Qiu et al. | Jul 2005 | A1 |
| 20050188074 | Voruganti et al. | Aug 2005 | A1 |
| 20050190787 | Kuik et al. | Sep 2005 | A1 |
| 20050216597 | Shah et al. | Sep 2005 | A1 |
| 20050223134 | Vasudevan et al. | Oct 2005 | A1 |
| 20050259644 | Huitema et al. | Nov 2005 | A1 |
| 20050259678 | Gaur | Nov 2005 | A1 |
| 20050286560 | Colman et al. | Dec 2005 | A1 |
| 20050289246 | Easton et al. | Dec 2005 | A1 |
| 20060015618 | Freimuth et al. | Jan 2006 | A1 |
| 20060015651 | Freimuth et al. | Jan 2006 | A1 |
| 20060031524 | Freimuth et al. | Feb 2006 | A1 |
| 20060039413 | Nakajima et al. | Feb 2006 | A1 |
| 20060072564 | Cornett et al. | Apr 2006 | A1 |
| 20060075119 | Hussain et al. | Apr 2006 | A1 |
| 20060080733 | Khosmood et al. | Apr 2006 | A1 |
| 20060098675 | Okuno | May 2006 | A1 |
| 20060101090 | Aloni et al. | May 2006 | A1 |
| 20060133267 | Alex et al. | Jun 2006 | A1 |
| 20060168649 | Venkat et al. | Jul 2006 | A1 |
| 20060200363 | Tsai | Sep 2006 | A1 |
| 20060206300 | Garg et al. | Sep 2006 | A1 |
| 20060209693 | Davari et al. | Sep 2006 | A1 |
| 20060221832 | Muller et al. | Oct 2006 | A1 |
| 20060221946 | Shalev et al. | Oct 2006 | A1 |
| 20060235977 | Wunderlich et al. | Oct 2006 | A1 |
| 20060265517 | Hashimoto et al. | Nov 2006 | A1 |
| 20060268841 | Nagaraj et al. | Nov 2006 | A1 |
| 20060274788 | Pong | Dec 2006 | A1 |
| 20060281451 | Zur | Dec 2006 | A1 |
| 20070011358 | Wiegert et al. | Jan 2007 | A1 |
| 20070033301 | Aloni et al. | Feb 2007 | A1 |
| 20070064737 | Williams | Mar 2007 | A1 |
| 20070070901 | Aloni et al. | Mar 2007 | A1 |
| 20070076623 | Aloni et al. | Apr 2007 | A1 |
| 20070083638 | Pinkerton et al. | Apr 2007 | A1 |
| 20070086480 | Elzur et al. | Apr 2007 | A1 |
| 20070110436 | Bennett | May 2007 | A1 |
| 20070143848 | Kraemer et al. | Jun 2007 | A1 |
| 20070162572 | Aloni et al. | Jul 2007 | A1 |
| 20070201474 | Isobe | Aug 2007 | A1 |
| 20070233892 | Ueno | Oct 2007 | A1 |
| 20080002731 | Tripathy et al. | Jan 2008 | A1 |
| 20080016511 | Hyder et al. | Jan 2008 | A1 |
| 20080043750 | Keels et al. | Feb 2008 | A1 |
| 20080089347 | Phillipi et al. | Apr 2008 | A1 |
| 20080091868 | Mizrachi et al. | Apr 2008 | A1 |
| 20080135415 | Han et al. | Jun 2008 | A1 |
| 20080168190 | Parthasarathy et al. | Jul 2008 | A1 |
| 20080232386 | Gorti et al. | Sep 2008 | A1 |
| 20080273532 | Bar-David et al. | Nov 2008 | A1 |
| 20090073884 | Kodama et al. | Mar 2009 | A1 |
| 20090172301 | Ebersole et al. | Jul 2009 | A1 |
| 20090222564 | Freimuth et al. | Sep 2009 | A1 |
| 20100023626 | Hussain et al. | Jan 2010 | A1 |
| 20100235465 | Thorpe et al. | Sep 2010 | A1 |
| Entry |
|---|
| Clark et al., “An Analysis of TCP Processing Overhead,” IEEE Communications Magazine, Jun. 1989, pp. 23-29. |
| Woodside et al., “The Protocol Bypass Concept for High Speed OSI Data Transfer,” Research Paper. Available at:http://citeseer.ist.psu.edu/cache/papers/cs/26104/http:zSzzSzwww.sce.carleton.cazSzftpzSzpubzSzcmwzSzbpjan90.pdf/woodside90protocol.pdf. |
| Rütsche et al., “TCP/IP on the Parallel Protocol Engine,” High Performace Networking, (IV, C-14), Elsevier Science Publishers, B.V. North Holland 1993. |
| Thia et al., “High-Speed OSI Protocol Bypass Algorithm with Window Flow Control,” IFIP WG6.4 Third International Workshop on Protocols for High-Speed Networks, Stockholm, Sweden, May 13-15, 1992, pp. 53-68. |
| Thia et al., “A Reduced Operation Protocol Engine (ROPE) for a Multiple-Layer Bypass Architecture,” Protocols for High-Speed Networks IV, 4th IFIP International Workshop, Aug. 10-12, 1994, Vancouver, B.C., Canada, pp. 224-239. |
| Rütsche et al., “Architectures of Multimedia Communication Subsystems,” IFIP Transactions; vol. C-23 archive, Proceedings of the IFIP TC6 International Conference on Information Networks and Data Communication table of contents, pp. 217-230, Year of Publication: 1994. |
| Dalton et al., “Afterburner: Architectural Support for High-Performance Protocols,” http://www.hpl.hp.com/techreports/93/HPL-93-46.pdf, Jul. 1993, 18 Pages. |
| TRM Technologies, Inc., “L4/L7 Switching,” Downloaded from http://www.trm.ca/pages/t-tech7.html on Feb. 16, 2006, 3 Pages. |
| Madsen et al., “Wireless Data Communication,” Fall 2003 Presentation, Wireless Networks Division (WING), Allborg University. |
| Yocum et al., “Anypoint: Extensible Transport Switching on the Edge,” Proceedings of the 4th USENIX Symposium on Internet Technologies and Systems, Mar. 26-28, 2003, Seattle, WA, USA. |
| International Search Report in PCT/US02/12679, dated Jul. 23, 2002. |
| Office Action in U.S. Appl. No. 10/474,500, mailed Oct. 4, 2007. |
| Office Action in U.S. Appl. No. 11/137,146, mailed Mar. 5, 2008. |
| Office Action in U.S. Appl. No. 11/137,140, mailed Feb. 5, 2008. |
| Office Action in U.S. Appl. No. 11/250,894, mailed Jun. 26, 2008. |
| Notice of Allowance in U.S. Appl. No. 10/474,500, mailed Jul. 1, 2008. |
| Allowed Claims from U.S. Appl. No. 10/474,500. |
| Office Action in U.S. Appl. No. 11/217,661, mailed Sep. 18, 2008. |
| Office Action in U.S. Appl. No. 11/313,003, mailed Aug. 22, 2008. |
| Office Action in U.S. Appl. No. 11/330,898, mailed Oct. 8, 2008. |
| Office Action in U.S. Appl. No. 11/137,146, mailed Nov. 3, 2008. |
| Office Action in U.S. Appl. No. 11/356,850 mailed Dec. 3, 2008. |
| U.S. Appl. No. 60/690,465, filed Jun. 14, 2005. |
| U.S. Appl. No. 60/718,418, filed Sep. 19, 2005. |
| Office Action in U.S. Appl. No. 11/282,933 mailed Feb. 20, 2009. |
| Office Action in U.S. Appl. No. 11/250,894 mailed Jan. 26, 2009. |
| Office Action in U.S. Appl. No. 11/137,140 mailed Mar. 31, 2009. |
| Office Action in U.S. Appl. No. 11/130,898 mailed Apr. 2, 2009. |
| Office Action in U.S. Appl. No. 11/747,793 mailed Jun. 8, 2009. |
| Notice of Allowance in U.S. Appl. No. 11/313,003, mailed Jun. 8, 2008. |
| Allowed Claims from U.S. Appl. No. 11/313,003. |
| Office Action in U.S. Appl. No. 11/217,661 mailed Jun. 9, 2009. |
| Pratt, Ian and Fraser, Keir, “Arsenic: A User-Accessible Gigabit Ethernet Interface,” INFOCOM 2001. Twentieth Annual Joint Conference of the IEEE Computer and Communications Societies. Proceedings. IEEE, vol. 1, Issue , 2001 pp. 67-76 vol. 1. |
| Office Action in U.S. Appl. No. 11/137,146, mailed Jun. 23, 2009. |
| Office Action in U.S. Appl. No. 11/735,861, mailed Aug. 6, 2009. |
| Office Action in U.S. Appl. No. 11/137,140, mailed Aug. 21, 2009. |
| Office Action in U.S. Appl. No. 11/747,650, mailed Aug. 27, 2009. |
| Office Action in U.S. Appl. No. 11/250,894, mailed Sep. 15, 2009. |
| Notice of Allowance in U.S. Appl. No. 11/356,850, mailed Jun. 26, 2009. |
| Allowed Claims from U.S. Appl. No. 11/356,850. |
| Office Action in U.S. Appl. No. 11/282,933, mailed Sep. 9, 2009. |
| Notice of Allowance in U.S. Appl. No. 11/330,898, mailed Sep. 23, 2009. |
| Allowed Claims in U.S. Appl. No. 11/330,898. |
| Notice of Allowance in U.S. Appl. No. 11/217,661 mailed Jan. 11, 2010. |
| Allowed Claims from U.S. Appl. No. 11/217,661. |
| Notice of Allowance in U.S. Appl. No. 11/282,933 mailed Dec. 31, 2009. |
| Allowed Claims from U.S. Appl. No. 11/282,933. |
| Office Action in U.S. Appl. No. 11/747,793, mailed Jan. 25, 2010. |
| Office Action in U.S. Appl. No. 11/735,861, mailed Jan. 25, 2010. |
| Office Action in U.S. Appl. No. 12/122,570, mailed Feb. 4, 2010. |
| Office Action in U.S. Appl. No. 11/137,146, mailed Feb. 4, 2010. |
| Notice of Allowance in U.S. Appl. No. 11/250,894, mailed Mar. 29, 2010. |
| Allowed Claims from U.S. Appl. No. 11/250,894. |
| Office Action in U.S. Appl. No. 11/747,650, mailed Apr. 15, 2010. |
| Office Action in U.S. Appl. No. 11/747,673, mailed Apr. 30, 2010. |
| Office Action in U.S. Appl. No. 12/255,112, mailed Dec. 16, 2010. |
| Office Action in U.S. Appl. No. 12/567,581, mailed Mar. 8, 2011. |
| Office Action in U.S. Appl. No. 12/752,719 mailed May 5, 2011. |
| Notice of Allowance in U.S. Appl. No. 12/255,112, mailed May 31, 2011. |
| Office Action in U.S. Appl. No. 11/735,861, mailed Apr. 15, 2011. |
| Notice of Allowance in U.S. Appl. No. 11/747,673, mailed Jun. 30, 2011. |
| Office Action in U.S. Appl. No. 11/735,861 dated Oct. 13, 2011. |
| Office Action in U.S. Appl. No. 12/643,897 dated Nov. 2, 2011. |
| Office Action in U.S. Appl. No. 13/249,077, dated Feb. 22, 2012. |
| Notice of Allowance in U.S. Appl. No. 12/643,897 dated Mar. 7, 2012. |
| Notice of Allowance in U.S. Appl. No. 11/137,140, mailed Jun. 30, 2010. |
| Allowed Claims in U.S. Appl. No. 11/137,140. |
| Notice of Allowance in U.S. Appl. No. 12/122,570, mailed Jul. 8, 2010. |
| Allowed Claims in U.S. Appl. No. 12/122,570. |
| Notice of Allowance in U.S. Appl. No. 11/747,650, mailed Jul. 8, 2010. |
| Allowed Claims in U.S. Appl. No. 11/747,650. |
| Final Office Action in U.S. Appl. No. 11/747,793, mailed Jul. 23, 2010. |
| Office Action in U.S. Appl. No. 12/645,324, mailed Aug. 25, 2010. |
| Office Action in U.S. Appl. No. 12/752,719, mailed Nov. 10, 2010. |
| Office Action in U.S. Appl. No. 12/567,581, mailed Nov. 3, 2010. |
| Office Action in U.S. Appl. No. 11/747,673, mailed Oct. 29, 2010. |
| Office Action in U.S. Appl. No. 11/735,861, mailed Oct. 27, 2010. |
| Office Action in U.S. Appl. No. 13/413,196, dated May 10, 2012. |
| Notice of Allowance in U.S. Appl. No. 13/413,196, mailed Aug. 31, 2012. |
| Office Action in U.S. Appl. No. 11/735,861 dated Nov. 7, 2012. |
| Hewlett Packard, “Using TCP/IP Offload Engine and Receive-Side Scaling to Improve Performance and Efficiency on HP Proliant Servers in Microsoft Windows Environments”, 2006, p. 1-8. |
| Boon S. Ang, “An Evaluation of an Attempt at Offloading TCP/IP Processing onto an i960RN-based iNIC”, 2001, Hewlett Packard, p. 1-33. |
| Line Provider, “TCP/IP offload Engine TOE”, 2002, p. 1-7, retreived from http://line-provider.com/whitepapers/tcpip-offloadengine-toe/. |
