Maintaining data unit order in a network switching device

A method of maintaining order for data units processed by a network device, the method comprising:

• receiving a data unit at the network device;
• dispatching the data unit to one of a plurality of parallel processors that generates a plurality of successive classifications for the data unit, each classification relating to a traffic flow to which the data unit belongs;
• progressing the data unit through a series of re-order queues determined based on the plurality of successive classifications for the data unit;
• and
• signaling, by the one of the plurality of parallel processors, for each successive classification, a re-order queue to which the data unit is to progress.

A method of maintaining order for data units processed by a network device, the method comprising:

• receiving a data unit at the network device;
• dispatching the data unit to one of a plurality of parallel processors that generates a plurality of successive classifications for the data unit, each classification relating to a traffic flow to which the data unit belongs;
• and
• progressing the data unit through a series of re-order queues determined based on the plurality of successive classifications for the data unit,
• where progressing the data unit through the series of re-order queues further includes:
• dequeueing the data unit from one of the re-order queues when the data unit is at the head of the one of the re-order queues and a command has been received for the data unit from one of the plurality of parallel processors.

An ordering component in a router, comprising:

• a plurality of input queues that receive data units incoming to the router, each data unit being enqueued into an input queue selected based on a physical interface at which the data unit is received by the router;
• a plurality of re-order queues that receive data units from outputs of the input queues or from outputs from the plurality of re-order queues;
• a switch that connects the outputs of the plurality of input queues to inputs of the plurality of re-order queues and outputs of the plurality of re-order queues to inputs of the plurality of re-order queues;
• and
• a control component that dequeues data units from the plurality of input queues and the plurality of re-order queues when a data unit is at the head of a queue and a command has been received for the data unit.

A method of maintaining order for data units processed by a network device, the method comprising:

• receiving a data unit at the network device;
• dispatching the data unit to one of a plurality of parallel processors that generates a plurality of successive classifications for the data unit, each classification relating to a traffic flow to which the data unit belongs;
• progressing the data unit through a series of re-order queues determined based on the plurality of successive classifications for the data unit;
• and
• enqueueing the data unit to an input queue determined based on a physical interface at which the data unit is received by the network device, an output of the input queue connecting to inputs of the re-order queues.