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

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Chapter 7 Automated RFC 2544 Testing
About the Back to Back Frames test
HST-3000 Ethernet Testing User’s Guide
207
Frame Loss test
test results
Frame Loss results are presented in a tabular format, illus-
trating the frame loss rate versus the percent of the band-
width. See
Figure 45 on page 226 for sample graphs and
result measurements.
About the Back to Back Frames test
Using the frame length and other settings such as the frame
type and encapsulation, the HST calculates the burst size
required to transmit back to back frames for the duration that
you specify as the Back to Back Max Trial Time. It then trans-
mits the burst of frames over the circuit. If the number of
frames transmitted carrying an Acterna payload does not
equal the number of received frames carrying an Acterna
payload (indicating that frames were lost during the transmis-
sion), the HST goes through the stages described for the
Throughput test (see
“About the Throughput test” on
page 199 ) until no frames are lost, or until the number of
frames per burst from the last successful burst exceeds the
Back to Back Frames Granularity by a 1 frame burst.
The test counts the number of frames received for each trial
(specified as the Number of Back to Back Frame Trials), and
each count 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 count. The test then uses
this count to calculate the average amount of time a burst can
be transmitted before a frame is dropped.
Back to Back
test results
Back to Back test results are presented in a table. See
Figure 46 on page 227 for sample result measurements.