System and method to implement a packet switch output buffer
AssigneeNortel Networks Limited
InventorsJim Meredith, Paul Gallo, Nanying Yin, Heather Achilles, Mike Fortuna
Life of this patent
Estimating the term…
Abstract
The present invention provides a system and method to implement a packet switch buffer. Incoming data packets are temporarily stored in an input buffer memory. Data packets in the input buffer memory are then examined to determine locations in an output buffer memory where the data packets should be transferred. Data packets in the input buffer memory are then transferred to the output buffer memory, such that data packets destined for a line card are written in an output memory block corresponding to the line card. Afterward, data packets in the output buffer memory are extracted and forwarded to designated output destinations.
Claims22
A packet switch system, comprising:
- a plurality of input queues in an input buffer memory, each of the input queues configured to store data packets;
- a plurality of output queues in an output buffer memory operatively coupled to the input buffer memory, each of the output queues configured to store those of the data packets destined for a port on a corresponding line card;
- a scheduler coupled to the plurality of output queues to extract data packets stored in the plurality of output queues in a permit-based round-robin service sequence;
- and
- a predetermined maximum byte count of data for each of the plurality of output queues, each maximum byte count limiting the number of data packets that may be extracted from each of the plurality of output queues during a queue service period.
An output buffer system in a packet switch, comprising:
- a plurality of output queues in an output buffer memory, each of the output queues configured to store those of the data packets destined for a port on a corresponding line card;
- a scheduler coupled to the plurality of output queues to extract data packets stored in the plurality of output queues in a permit-based round-robin service sequence;
- and
- a predetermined maximum byte count of data for each of the plurality of output queues, each maximum byte count limiting the number of data packets that may be extracted from each of the plurality of output queues during a queue service period.
A method of switching data packets, comprising:
- storing incoming data packets in an input buffer memory;
- examining an output destination parameter included in the data packets to determine a locations in one of a plurality of output queues in an output buffer memory where the data packets should be transferred;
- transferring data packets from the input buffer memory to the determined output queue in the output buffer memory, such that date packets destined for a port on a line card are written in the one of the output queue corresponding to the port on the line card;
- employing a permit-based round-robin service sequence to extract data packets from output queues in the output buffer memory;
- and
- limiting the number of data packets that may be extracted from each of the output queues during a queue service period with a predetermined maximum byte count of data for each of the output queues.
A packet switching system, comprising:
- means for storing incoming data packets in an input buffer memory;
- means for examining an output destination parameter included in the data packets to determine a locations in one of a plurally of output queues in an output buffer memory where the data packets should be transferred;
- means for transferring data packets from the input buffer memory to the determined output queue in the output buffer memory, such that data packets destined for a port on a line card are written in the one of the output queues corresponding to the port on the line card;
- means for employing a permit-based round-robin service sequence to extract packets from output queues in the output buffer memory;
- and
- means for limiting the number of data rackets that may be extracted from each of the output queues during a queue service period with a predetermined maximum byte count of data for each of the output queues.
Dependencies are inferred from the claim text.