JDS Uniphase IP Video Test Option HST-3000, User Manual

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Chapter 7 Automated RFC 2544 Testing
About the System Recovery test
HST-3000 Ethernet Testing User’s Guide
205
The test measures the average packet jitter and maximum
packet jitter for each trial (specified as the Number of Packet
Jitter Trials), and then each measurement is added to a
running total. After all of the trials are complete, the running
total is divided by the number of trials to come up with a total
trial average measurement.
If the Throughput test reached the lowest bandwidth limit
without ever successfully receiving all transmitted frames (in
otherworlds, it lost frames), the packet jitter measurements
will also be unavailable. Unavailable average or maximum
average measurements are not included in the total trial
average.
Packet Jitter
test results
Packet Jitter results are presented statistically. See Figure 43
on page 224 for sample result measurements.
Pass/fail
threshold
You can configure the test to optionally indicate whether the
Packet Jitter test passed or failed. To do so, you specify the
Packet Jitter Pass Threshold. For each frame length you
selected, the test compares the average packet jitter for the
trial to the value that you specified as the threshold. If the
average packet jitter is less than or equal to that specified for
the threshold, the test indicates that the test passed. If it
exceeds the threshold, the test indicates that the test failed.
About the System Recovery test
If you intend to run the System Recovery test, the Expert
RFC 2544 mode must be Symmetric, and you must also
select and run the Throughput test. The HST uses the
Throughput test to determine the maximum bandwidth at
which no frames were lost, then the System Recovery test
transmits traffic at 110% of the bandwidth (referred to as the
“overload rate”) to force the receiving network element to drop