Patent ID: 7701852

Claim:
A method for analyzing performance of a communications network, comprising: measuring a packet-size-dependent minimum delay through at least one routing device in the communications network, the packet-size-dependent minimum delay being experienced by a packet, wherein the packet-size-dependent minimum delay includes an amount of time that elapses during which the routing device makes a forwarding decision, divides the packet into cells, transmits the packet across a switching fabric, reassembles the packet, and delivers the packet to an output queue, 1) wherein the amount of time is based in-part on a first timestamp that is created prior to every byte of the packet entering an input interface, in addition to, a duration of time required to finish transferring every byte of the first packet into the input interface, and (2) wherein the amount of time is also based in-part on a second timestamp that is created prior to every byte of the packet fully exiting an output interface, in addition to, a duration of time required to finish transferring every byte of the first packet out of the output interface; and reporting the packet-size-dependent minimum delay, wherein reporting comprises exporting information describing the packet-size-dependent minimum delay using network protocols.