EXFO FTB-860, User Manual

Page: 96 / 409

RFC 2544 Test Setup and Results
84
FTB-860/880
Subtests Configuration
Back-to-Back Configuration
The objective of this test is to find the maximum number of frames that can
be sent at maximum throughput without frame loss. A burst of frames
(
Max. Burst Duration ) is sent with minimum inter-frame gaps to the
device under test and the number of forwarded frames is counted. If the
count of transmitted frames is equal to the number of forwarded frames,
the length of the burst is increased and the test is rerun. If the number of
forwarded frames is less than the number of transmitted frames, the length
of the burst is reduced and the test is rerun. The Back-to-Back value is the
number of frames in the longest burst that the device under test (DUT) can
handle without the loss of any frames. The test performs the number of
defined trials (
Number of Trials ). The Accuracy ( Frames ) settings specify
how precise that result must be. The test is performed for each defined
frame size.
Note:
Back-to-Back must be enabled from
Global Configuration
on page 77.

Max. Burst Duration (s) : Enter the Max. Burst Duration in seconds.
Choices are
1
to
5
seconds. The default setting is
2
seconds.

Accuracy (Frames) : Enter the Accuracy measurement value in frames.
Choices are
1
to
50
frames. The default setting is
1
.

Number of Trials : Select the number of trials to average. Choices are 1
to
100
trials. The default setting is
1
trial.

Threshold : Set the threshold value in percentage of frames per burst
for the test. If the determined Back-to-Back value is greater or equal to
the threshold value, the test is declared as PASS. If the determined
Back-to-Back value for a specific frame size is lower than the threshold
value, the test is declared as FAIL. This value should range from
0.000
to
100.000
and applies to all the 7 RFC 2544 frame sizes or for the 7
user-defined frame sizes. The default setting is 100.000 .
Note:
Threshold parameter will be editable only when the RFC 2544 Pass/Fail
Verdict parameter is Enabled in
Global Configuration on page 77.