Patent ID: 8576713

Claim:
A port unit, comprising: a traffic receiver to receive flow control packets from a network under test; and a traffic generator pipeline to generate and transmit test traffic over the network under test, the test traffic including a plurality of interleaved packet streams, each packet stream associated with one of a plurality of flow control groups, the traffic generator pipeline comprising: a scheduler to determine a sequence in which packets belonging to the plurality of packet streams are generated, and two or more processing engines, including a first processing engine and a last processing engine, to perform sequential stages of a packet generation process, wherein the first processing engine inputs data indicative of the packet sequence from the scheduler and outputs flow control data to the scheduler, the last processing engine outputs competed packets ready for transmission, selectively pausing packet streams associated with one or more paused flow control groups in accordance with the received flow control packets, each processing engine except the last processing engine outputs packet forming data to a subsequent processing engine in the pipeline, and each processing engine except the first processing engine outputs flow control data to a previous processing engine in the pipeline.