Abstract: Systems and methods for scheduling data packets in a network processor are disclosed. Embodiments provide a network processor that comprises a best-effort scheduler with a minimal calendar structure for addressing schedule control blocks. In one embodiment, a three-entry calendar structure provides for weighted best effort scheduling. Each of a plurality different flows has an associated schedule control block. Schedule control blocks are stored as linked lists in a last-in-first-out buffer. Each calendar entry is associated with a different linked list by storing in the calendar entry the address of the first-out schedule control block in the linked list. Each schedule control block has a counter and is assigned a weight according to the bandwidth priority of the flow to which the corresponding packet belongs.

Abstract: A system and method for computing a blind checksum includes a host Ethernet adapter (HEA) with a system for receiving a packet. The system determines whether or not the packet is in Internet protocol version four (IPv4). If the packet is not in IPv4, the system computes the checksum of the packet. If the packet is in IPv4, the system determines whether the packet is in transmission control protocol (TCP) or user datagram protocol (UDP). If the packet is not in either of TCP or UDP the system attaches a pseudo-header to the packet and computes the checksum of the packet based on the pseudo-header and the IPv4 standard.

Abstract: A system and method for reducing latency in a host Ethernet adapter (HEA) includes the following. First, the HEA receives a packet with an internet protocol (IP) header and data in the HEA. The HEA parses a connection identifier from the IP header and accesses a negative cache in the HEA to determine if the connection identifier is not in a memory external to the HEA. The HEA applies a default treatment to the packet if the connection identifier is not in the memory, thereby reducing latency by decreasing access to the memory.

Abstract: A method and system for receiving packets in a computer network are disclosed. The method and system include providing at least one receive port, a buffer, a scheduler, and a wrap port. The buffer has an input coupled with the at least one receive port and an output. The scheduler has a first input coupled to the output of the buffer, a second input coupled to the wrap port, and an output.

Abstract: Method and apparatus for implementing use of a network connection table. In one aspect, searching for network connections includes receiving a packet, and zeroing particular fields of connection information from the packet if a new connection is to be established. The connection information is converted to an address for a location in a direct table using a table access process. The direct table stores patterns and reference information for new and existing connections. The connection information is compared with at least one pattern stored in the direct table at the address to find reference information for the received packet.

Abstract: A system and method for parsing, filtering, and computing the checksum in a host Ethernet adapter (HEA) that is coupled to a host. The method includes receiving a part of a frame, wherein a plurality of parts of a frame constitute a entire frame. Next, parse the part of a frame before receiving the entire frame. The HEA computes a checksum of the part of a frame. The HEA filters the part of a frame based on a logical, port-specific policy and transmits the checksum to the host.

Abstract: Providing communications between operating system partitions and a computer network. In one aspect, an apparatus for distributing network communications among multiple operating system partitions includes a physical port allowing communications between the network and the computer system, and logical ports associated with the physical port, where each logical port is associated with one of the operating system partitions. Each of the logical ports enables communication between a physical port and the associated operating system partition and allows configurability of network resources of the system. Other aspects include a logical switch for logical and physical ports, and packet queues for each connection and for each logical port.

Abstract: A system and method in accordance with the present invention allows for an adapter to be utilized in a server environment that can accommodate both a 10 G and a 1 G source utilizing the same pins. This is accomplished through the use of a high speed serializer/deserializer (high speed serdes) which can accommodate both data sources. The high speed serdes allows for the use of a relatively low reference clock speed on the NIC to provide the proper clocking of the data sources and also allows for different modes to be set to accommodate the different data sources. Finally the system allows for the adapter to use the same pins for multiple data sources.

Abstract: Method and apparatus for providing a checksum in a network transmission. In one aspect of the invention, a checksum for a packet to be transmitted on a network is determined by retrieving packet information from a storage device, the packet information to be included in the packet to be transmitted. A blind checksum value is determined based on the retrieved packet information, and the blind checksum value is adjusted to a protocol checksum based on descriptor information describing the structure of the packet. The protocol checksum is inserted in the packet before the packet is transmitted.

Abstract: A method and system for performing a lookup for a packet in a computer network are disclosed. The packet includes a header. The method and system include providing a parser, providing a lookup engine coupled with the parser, and providing a processor coupled with the lookup engine. The parser is for parsing the packet for the header prior to receipt of the packet being completed. The lookup engine performs a lookup for the header and returns a resultant. In one aspect, the lookup includes performing a local lookup of a cache that includes resultants of previous lookups. The processor processes the resultant.

Abstract: A communication network used to link information handling systems together utilizes a switching network to transmit data among senders and receivers. Each individual packet of data is described and controlled by an FCB. The bandwidth associated with the storing and distribution of data is optimized by chaining the data packets in different types of queues, or operating without chaining outside a queue. When a frame is in an output queue, the third word contains an RFCBA for egress of the frame to a line port, and an MCID for ingress from an output queue to a switch port. The RFCBA and the MCID have multicast capabilities. The format does not require a third word when a frame is in an input queue.

Abstract: Systems and methods for implementing counters in a network processor with cost effective memory are disclosed. Embodiments include systems and methods for implementing counters in a network processor using less expensive memory such as DRAM. A network processor receives packets and implements accounting functions including counting packets in each of a plurality of flow queues. Embodiments include a counter controller that may increment counter values more than once during a R-M-W cycle. Each time a counter controller receives a request to update a counter during a R-M-W cycle that has been initiated for the counter, the counter controller increments the counter value received from memory. The incremented value is written to memory during the write cycle of the R-M-W cycle. A write disable unit disables writes that would otherwise occur during R-M-W cycles initiated for the counter during the earlier initiated R-M-W cycle.

Abstract: A mechanism for offloading the management of send queues in a split socket stack environment, including efficient split socket queue flow control and TCP/IP retransmission support. As consumers initiate send operations, send work queue entries (SWQEs) are created by an Upper Layer Protocol (ULP) and written to the send work queue (SWQ). The Internet Protocol Suite Offload Engine (IPSOE) is notified of a new entry to the SWQ and it subsequently reads this entry that contains pointers to the data that is to be transmitted. After the data is transmitted and acknowledgments are received, the IPSOE creates a completion queue entry (CQE) that is written into the completion queue (CQ). After the CQE is written, the ULP subsequently processes the entry and removes it from the CQE, freeing up a space in both the SWQ and CQ. The number of entries available in the SWQ are monitored by the ULP so that it does not overwrite any valid entries.

Abstract: Systems and methods for implementing multi-frame control blocks in a network processor are disclosed. Embodiments include systems and methods to reduce long latency memory access to less expensive memory such as DRAM. As a network processor in a network receives packets of data, the network processor forms a frame control block for each packet. The frame control block contains a pointer to a memory location where the packet data is stored, and is thereby associated with the packet. The network processor associates a plurality of frame control blocks together in a table control block that is stored in a control store. Each table control block comprises a pointer to a memory location of a next table control block in a chain of table control blocks. Because frame control blocks are stored and accessed in table control blocks, less frequent memory accesses may be needed to keep up with the frame rate of packet transmission.

Abstract: Systems and methods for adaptively mapping system memory address bits into an instruction tag and an index into the cache are disclosed. More particularly, hardware and software are disclosed for observing collisions that occur for a given mapping of system memory bits into a tag and an index. Based on the observations, an optimal mapping may be determined that minimizes collisions.

Abstract: Methods, computer readable programs and network processor systems appropriate for IP fragmentation and reassembly on network processors comprising a plurality of buffers and buffer control blocks, the buffer control blocks comprising a buffer usage field, the buffer usage field having a value set responsive to a quantity of frame data fragments, wherein the network processor system associates a buffer control block with each buffer and frees a first buffer after reading a frame data fragment responsive to the first buffer control block buffer usage field value indicating only one frame data fragment is present in the first buffer.

Abstract: A method and apparatus are used for finding the longest prefix match in a variable length prefix search when searching a direct table within a routing table structure of a network processor. The search through the routing table structure is expedited by hashing a first segment of an internet protocol address with a virtual private network number followed by concatenating the unhashed bits of the IP address to the result of the hash operation to form an input key. Patterns are compared a bit at a time until an exact match or the best match is found. The search is conducted in a search tree that provides that the matching results will be the best possible match.

Abstract: Systems and methods for distributing thread instructions in the pipeline of a multi-threading digital processor are disclosed. More particularly, hardware and software are disclosed for successively selecting threads in an ordered sequence for execution in the processor pipeline. If a thread to be selected cannot execute, then a complementary thread is selected for execution.

Abstract: Apparatus and method for storing network frame data which is to be modified. A plurality of buffers stores the network data which is arranged in a data structure identified by a frame control block and buffer control block. A plurality of buffer control blocks associated with each buffer storing the frame data establishes a sequence of the buffers. Each buffer control block has data for identifying a subsequent buffer within the sequence. The first buffer is identified by a field of a frame control block as well as the beginning and ending address of the frame data. The frame data can be modified without rewriting the data to memory by altering the buffer control block and/or frame control block contents without having to copy or rewrite the data in order to modify it.

Abstract: A method for shaping network traffic in a computer network is described for packet data networks. The method includes one or more packet queues for traffic having a plurality of different desired packet transfer rates, each queue being assigned to a connection having a predetermined desired packet transfer rate. Each incoming data packet is directed to the appropriate queue. Each of a plurality of timing circuits operate at a different frequency in a series of frequencies. The frequencies are selected so that the desired packet transfer rate for a connection can be established by summing outputs from more than one of the timing circuits.