3com Corporation

Hewlett-packard Company

Chin-Li Mou

Chi-Lie Wang

Li-Jau Yang

Kap Soh

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

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.

Growing community of inventors

San Jose, CA, United States of America

Chin-Li Mou