US 2003/0223458 A1 · Using reassembly queue sets for packet reassembly

Abstract

A system for efficiently reassembling packets from cells received on independent switching fabrics according to a serial high speed interface (HSI) protocol. The system includes redundancy in that fabrics may be removed by skipping the fabrics in striping and reassembly sequences. When fabrics are added, the fabrics are included in the striping and reassembly sequences. The system is efficient due in part to in-order transmission of cells serially across multiple fabrics. Full fabric bandwidth is thereby utilized without reordering overhead. Since packets are striped across all available fabrics, load is balanced across the fabrics.

Claims21

Dependent claims

A method of reassembling packets received across a plurality of switching fabrics, comprising:

associating a reassembly queue set (RQS) with a traffic class, wherein said RQS includes a plurality of reassembly queues;
associating a first queue of said RQS with a switching fabric of a plurality of switching fabrics;
receiving cells, wherein each cell has an associated traffic class, and wherein each cell is received on one of said plurality of switching fabrics;
enqueuing a first cell of the received cells in said first queue in accordance with the associated traffic class of said first cell and the switching fabric on which said first cell was received;
dequeuing cells in round robin fashion from said plurality of reassembly queues;
and
reassembling packets from the dequeued cells.

4 more elements

A system for reassembling packets received across a plurality of switching fabrics, comprising:

a packet memory;
a receive interface configured to receive cells striped across a plurality of switching fabric modules via respective high speed interfaces (HSIs) for storage in said packet memory;
a plurality of reassembly queues configured to queue received cells, wherein said plurality of reassembly queues are logically divided into reassembly queue sets (RQSs) that include one reassembly queue per switching fabric module of said plurality of switching fabric modules;
a packet constructor configured to:
accumulate cells in-order as said cells are dequeued from said reassembly queues;
reassemble one or more of said cells into a packet when an end-of-packet (EOP) cell is dequeued from one of said reassembly queues;
a packet queue configured to enqueue said packet;
and
a transmit interface configured to dequeue said packet and send said packet from said packet memory.

6 more elements

A packet forwarding device, comprising:

one or more ingresses, wherein each ingress includes a plurality of unicast ingress queues and a plurality of multicast ingress queues;
a plurality of switching fabrics respectively coupled to each of said one or more ingresses by high speed interfaces (HSIs), wherein each switching fabric includes a plurality of buffers that correspond to said unicast ingress queues;
and
one or more egresses respectively coupled to each of said plurality of switching fabrics by HSIs, wherein each egress includes:
a plurality of unicast reassembly queue sets (RQSs) that correspond to said unicast ingress queues, wherein said unicast RQSs each include a reassembly queue that corresponds to one of said switching fabrics;
and
a plurality of multicast RQSs that correspond to said multicast ingress queues, wherein said multicast RQSs each include a reassembly queue that corresponds to one of said switching fabrics.

4 more elements

Dependencies are inferred from the claim text.

Using reassembly queue sets for packet reassembly

Life of this patent

Using reassembly queue sets for packet reassembly

Life of this patent

Abstract

Claims21