Methods, systems, and computer readable media for precise measurement of switching latency of packet switching devices

A system for measurement of switching latency of a packet switching device, the system comprising:

• a network equipment test device including at least one processor and further comprising:
• a transmit module for transmitting frames to a device under test;
• a receive module receiving one of the transmitted frames from the device under test;
• and
• a latency calculation module for determining a measured latency of the device under test based on a difference between a time that the one frame was transmitted to the device under test and a time that the one frame was received from the device under test, determining an indication of backlog latency of the device under test caused by the device under test inserting virtual lane markers in traffic transmitted to the network equipment test device, wherein determining an indication of the backlog latency includes calculating an amount of latency caused by insertion of the virtual lane marker that remains after the device under test reduces an interframe gap to gain back bandwidth lost from the insertion of the virtual lane marker and quantifying the backlog latency over time from an initial value following transmission of the virtual lane marker and as the backlog latency decreases due to transmissions of buffered data by the device under test during intervals after transmission of the virtual lane marker when the device under test reduces the interframe gap, and reporting the indication of the backlog latency of the device under test.

A non-transitory computer readable medium having stored thereon executable instructions that when executed by the processor of a computer control the computer to perform steps comprising:

• in a network equipment test device including at least one processor:
• transmitting frames to a device under test;
• receiving one of the transmitted frames from the device under test;
• determining a measured latency of the device under test based on a difference between a time that the one frame was transmitted to the device under test and a time that the one frame was received from the device under test;
• determining an indication of a backlog latency of the device under test caused by the device under test inserting a virtual lane marker in traffic transmitted to the network equipment test device, wherein determining an indication of the backlog latency includes calculating an amount of latency caused by insertion of the virtual lane marker that remains after the device under test reduces an interframe gap to gain back bandwidth lost from the insertion of the virtual lane marker and quantifying the backlog latency over time from an initial value following transmission of the virtual lane marker and as the backlog latency decreases due to transmissions of buffered data by the device under test during intervals after transmission of the virtual lane marker when the device under test reduces the interframe gap;
• and
• reporting the indication of the backlog latency.