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Description:
NOT E
Making Measurements
Measuring Round Trip Delay
Measuring Round Trip Delay
The time taken for voice or data traffic to pass through the network is very important
as excessive delay adds distortion. Speech is particularly affected by delays longer
than 150 ms.
Round Trip Delay is a measurement of the total delay on the 'go' and 'return' legs of
a duplex path and is typically in the order of milliseconds.
HP ProBER 2 measures the time taken for a test pattern to be transmitted over the
'go' and 'return' legs of a duplex network path.
A test pattern is transmitted in an n × 64 kb/s path (or 2 Mb/s unframed path) and a
timer is set running. A loopback is manually applied to the network equipment to
return the test signal.
The received pattern stops the timer and the round trip delay is calculated.
1. Round trip delay is only possible at 2 Mb/s Line Rate.
2. Any error measurement must be stopped before the delay measurement can be
made.
3. The delay measurement must be terminated before an error measurement can be
started.
6-11
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