Lantronix SISPM1040-3166-L Web User Guide Rev G PDF 14.13 MB - Page 431

Transition Networks SISPM1040-3xxx-L Web User Guide Latency Test Parameters Note: Latency test depends on the Throughput test. Both must be enabled and configured for the Latency test to work. Enable : Check to enable the latency sub-test. The latency test measures the round-trip time of frames leaving the near-end until they get back to the near-end. Y.1731 TST or LBM frames are transmitted at the maximum rate determined by the throughput test less 200 Kbps. Every so many seconds, a Y.1731 1DM or DMM frame is transmitted and the time from this frame leaves the switch until it comes back is measured. If more than two 1DM frames are transmitted during a trial, also the delay variation will be part of the generated report. Selecting the latency test causes the throughput test to be selected automatically. Trial Duration : The time - in seconds - to transmit Y.1731 TST or LBM frames at a given rate and frame size. This is known as a "trial". Valid range is 10 - 1800 with a default of 120 seconds. Delay Measurement Interval : This controls the period - in seconds - at which Y.1731 1DM frames are transmitted. The first 1DM frame is transmitted this number of seconds after the trial has started. The total number of transmitted 1DM frames in one trial therefore depends on the configured trial duration. Valid range is 1 - 60 with a default of 10 seconds. Allowed Frame Loss : In some cases, it may be acceptable to have loss on a connection. The allowed loss can be specified with this parameter. A trial is considered failing if more than this percentage of frames are lost. Valid range is 0 - 100 with a default of 0 ‰ of the number of transmitted frames. Frame Loss Test Parameters Enable : Check to enable the frame loss sub-test. The frame loss test measures frame loss at configurable transmission rates. It starts at the configured maximum rate and steps down by the configured step size and stops when two consecutive trials succeed (test succeeded in that case) or the minimum rate is reached (test failed in that case). For a trial to succeed, two criteria must be fulfilled: • Test must have zero frame loss. • The actual Tx rate must be greater than the applied Tx rate minus the step rate. The rates reported are seen by the customer. Encapsulation possibly added on the network-facing side (e.g. a VLAN tag) may cause the actual Tx rate to be smaller than the applied Tx rate while the frame loss is still measured as zero. Hence this additional criterion. When this situation occurs, software may skip steps that it "knows" will fail in order to quickly get to the rates that are expected passing. For each trial, the report displays the frame loss ratio. Trial Duration : The time - in seconds - to transmit Y.1731 TST or LBM frames at a given rate and frame size. This is known as a "trial". Valid range is 1 - 1800 with a default of 60 seconds. Minimum Rate : The minimum rate - in ‰ of the egress port's line rate - to transmit Y.1731 TST or LBM frames at. Valid range is 1 - 1000 with a default of 800 ‰ of the line rate. Maximum Rate : The highest (and first) rate - in ‰ of the egress port's line rate - to transmit Y.1731 TST or LBM frames at. Valid range is 1 - 1000 with a default of 1000 ‰ of the line rate. 33763 Rev. G https://www.transition.com Page 431 of 496