| 摘要 |
Aspects of a high-precision packet train generation process are distributed among several distinct processing elements. In some embodiments a control processor configures a packet-processing unit with a packet train context that includes details such as the number of packets to be generated and the headers to be included in the packets. The packet-processing unit takes a packet to be used in the packet train and recirculates it a number of times, as specified by the packet train context. The recirculated packets, with the appropriate headers inserted, are forwarded to a traffic-shaping queue in queuing hardware. The traffic-shaping queue is configured to output the forwarded packets with a constant inter-packet gap. Thus, the generation of the multiple packets in the packet train is handled by the packet-processing unit, while the precise inter-packet timing is provided by the traffic-shaping queue in the queuing hardware. |
| 主权项 |
1. A method for generating a high-precision packet train in a packet processing platform that comprises a packet-processing unit and queuing hardware, said queuing hardware being configured to output data at a network bitrate, the method comprising:
receiving a packet train context at the packet-processing unit, the packet train context indicating a number of packets to be generated for the packet train and including a packet header designating a traffic-shaping queue in the queuing hardware; receiving configuration information at the queuing hardware, said configuration information establishing a constant inter-packet gap for packets output by the traffic-shaping queue designated by the packet header; receiving a packet at the packet-processing unit, the packet including information identifying the packet train context; injecting the packet with the packet header, using the packet-processing unit, and forwarding the packet, including the packet header, to the queuing hardware for handling by the traffic-shaping queue designated by the packet header; recirculating the packet in the packet-processing unit and forwarding recirculated packets to the queuing hardware until the number of forwarded packets equals the number of packets indicated by the packet train context, wherein said forwarding is performed at a rate sufficient to keep the traffic-shaping queue at least fully subscribed, given the constant inter-packet gap for packets output by the traffic-shaping queue; and outputting the forwarded packets from the traffic-shaping queue, at the network bitrate, such that the output packets are separated by the constant inter-packet gap. |
