3com Corporation

Cisco Technology, Inc.

Hewlett-packard Company

Li-Jau Yang

Chi-Lie Wang

Daniel Christian Biederman

Kap Soh

Chin-Li Mou

Ngo Thanh Ho

Richard L Traber

Rich Traber

Chi-Le Wang

An apparatus for providing link layer security in a Physical Layer Transceiver (PHY) is disclosed. In one embodiment, the apparatus may comprise analog circuitry configured to interface with a data transmission medium, digital circuitry configured to interface with a Media Access Controller (MAC); and a crypto engine coupled to the digital circuitry. Single interface and multiple interface schemes are provided to control both PHY and crypto functions. Embodiments are disclosed where the PHY controls the crypto device, and where the crypto device controls the PHY.

Method and apparatus of communicating security/encryption information to a physical layer transceiver

A plurality of virtual paths in a network interface between a host port and a network port are managed according to respective priorities using dynamic buffer allocation. Thus, multiple levels of quality of service are supported through a single physical network port. Variant processes are applied for handling packets which have been downloaded to a network interface, prior to transmission onto the network. The network interface also includes memory used as a transmit buffer, that stores data packets received from the host computer on the first port, and provides data to the second port for transmission on the network. A control circuit in the network interface manages the memory as a plurality of first-in-first-out FIFO queues having respective priorities. Logic places a packet received from the host processor into one of the plurality of FIFO queues according to a quality of service parameter associated with the packets. Logic transmits the packets in the plurality of FIFO queues according to respective priorities. Logic dynamically allocates the memory using a list of buffer descriptors for corresponding buffers in said memory. The list of buffer descriptors comprises a free buffer list and a used buffer list for each of the virtual paths served by the system. A used buffer descriptor is released from the used buffer list, after the data stored in the corresponding used buffer has been transmitted, to the free buffer list for a virtual path which has the largest amount traffic or which has the smallest number of free buffers in its free buffer list.

Network interface supporting of virtual paths for quality of service with dynamic buffer allocation

An apparatus for providing link layer security in a Physical Layer Transceiver (PHY) is disclosed. In one embodiment, the apparatus may comprise analog circuitry configured to interface with a data transmission medium, digital circuitry configured to interface with a Media Access Controller (MAC); and an crypto engine coupled to the digital circuitry.

Method and apparatus of integrating link layer security into a physical layer transceiver

A plurality of virtual paths in a network interface between a host port and a network port are managed according to respective priorities. Thus, multiple levels of quality of service are supported through a single physical network port. Variant processes are applied for handling packets which have been downloaded to a network interface, prior to transmission onto the network. The network interface also includes memory used as a transmit buffer, that stores data packets received from the host computer on the first port, and provides data to the second port for transmission on the network. A control circuit in the network interface manages the memory as a plurality of first-in-first-out FIFO queues having respective priorities. Logic places a packet received from the host processor into one of the plurality of FIFO queues according to a quality of service parameter associated with the packets. Logic transmits the packets in the plurality of FIFO queues according to respective priorities. The transmit packet buffer may be statically or dynamically allocated memory.

Network interface supporting virtual paths for quality of service

A hardware packet accelerator parses incoming packets to retrieve header data for building a frame status and for verifying the incoming packets are part of an established connection with a host. The accelerator includes a connection database that allows retrieval of connection information based on an index constructed from a hashed TCP connection address. The frame status comprises information needed to perform packet re-assembly and is stored in a memory that is local (directly accessible) by a processing device that performs the packet re-assembly. Among other advantages, the processing device does not need to read packet header data from a packet buffer, saving large amounts of header data retrieval time.

Method and apparatus for hardware assisted TCP packet re-assembly

An automatic scan test enable signal assertion system and method responds to transitions in signals communicated via selected pins that are not dedicated solely to testing operations. Pins are utilized to communicate a trigger signal and a stage progression signal. The trigger signal provides an indication to initiate a scan test enable signal assertion or deassertion and the stage progression signal controls the progress of the scan test enable activation or deactivation initiation. A scan test enable trigger sensing component provides an assertion or deassertion notification when logical values of a trigger signal captured during multiple stages provide an indication to begin a scan test enable signal assertion or deassertion. A staging component advances the logical values through stages in accordance with a progression signal and issues an asserted or deasserted scan test enable signal based upon the assertion or deassertion notification from the scan test enable trigger sensing component.

Automatic activation of ASIC test mode

A system and method for managing power consumption on a network interface card involves connecting constantly running clocks to a small amount of logic on the network interface card. The logic is used to monitor activity on the network interface card, and in response to events enable the clocks for functional blocks within the chip, on an as needed basis. Through dynamically controlled clocks, power consumption can be reduced significantly, and the network interface card remains in a state that is able to react efficiently to external events related to transmission of packets, reception of packets and functions related to the management of the network interface.

Network interface with power conservation using dynamic clock control

Hardware only transmission control protocol segmentation for a high performance network interface card. Specifically, one embodiment of the present invention includes a circuit for implementing transmission control protocol (TCP) segmentation. The circuit includes a segmentation circuit coupled to receive a descriptor from a host device which corresponds to data. The segmentation circuit utilizes the descriptor to generate other descriptors that describe each frame segment. Furthermore, the circuit also includes a data download circuit coupled to the segmentation circuit to receive the frame segment descriptors. Specifically, the data download circuit retrieves the data from a memory. Moreover, the circuit includes a medium access control circuit coupled to the data download circuit to receive the data in a frame segment.

Hardware only transmission control protocol segmentation for a high performance network interface card

A method and system for priority arbitration in a computer environment having a shared resource capable of servicing a plurality of devices. In one embodiment, the present invention assigns an initial priority order to the plurality of devices such that those devices have priorities which are distinct. The present invention then identifies those of the plurality of devices which have issued service requests to the shared resource in a first clock cycle as requesting devices. Provided that there are more than one requesting device in the first clock cycle, the present invention selects one of the requesting devices to be serviced by the shared resource in a second clock cycle following the first clock cycle, where the selected device has the highest of the priorities among the requesting devices based on the initial priority order. The present invention also reassigns the priorities among the plurality of devices such that the selected device is assigned the lowest one of the priorities. This embodiment of the present invention thus provides a novel method and system for single cycle priority arbitration which is fair and which does not require extra memory storage for its implementation.

Single cycle modified round-robin arbitration with embedded priority

Support for priority and IP security packets, and other protocols at the network interface level and in conjunction with FIFO-based packet buffers is provided by allowing out of order processing of certain packets in the FIFO. The optimized character of FIFO for sequential transfer is maintained, while particular types of packets are processed out of order to achieve minimum latency and maximum data security in an intelligent network interface card. A buffer stores data packets in an order of receipt. Logic is included in the network interface to transfer packets out of the buffer according to the order of receipt, and according to the respective packet types so that packets having a particular packet type are transferred out of the order of receipt relative to packets having other packet types.

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San Jose, CA, United States of America

Li-Jau Yang