4 TRex Traffic Generator (TG) is used for measuring latency across 2-Node
5 and 3-Node SUT server topologies. TRex integrates `A High Dynamic Range
6 Histogram (HDRH) <http://hdrhistogram.org/>`_ code providing per packet
7 latency distribution for latency streams sent in parallel to the main
8 load packet streams. Packet latency is measured using following
11 - Latency tests are performed at following packet load levels:
13 - No-Load: latency streams only.
14 - Low-Load: at 10% PDR.
15 - Mid-Load: at 50% PDR.
16 - High-Load: at 90% PDR.
17 - NDR-Load: at 100% NDR.
18 - PDR-Load: at 100% PDR.
20 - Latency is measured for all tested packet sizes except IMIX due to
22 - TG sends dedicated latency streams, one per direction, each at the
23 rate of 9 kpps at the prescribed packet size; these are sent in
24 addition to the main load streams.
25 - TG reports Min/Avg/Max and HDRH latency values distribution per stream
26 direction, hence two sets of latency values are reported per test
28 - Reported latency values are aggregate across tested topology.
29 - +/- 1 usec is the measurement accuracy advertised by TRex TG for the
31 - TG setup introduces an always-on Tx/Rx interface latency of about 2
32 * 2 usec per direction induced by TRex SW writing and reading packet
33 timestamps on CPU cores.