User manual

4-26
Chapter 4
Analyze Network
VoIP - cont.
VoIP example - cont.
NOTE: Select another Test button visible on the screen or by scrolling
to the right or left with the white arrows or select the Exit button.
Media Stream - cont.
RESTARTS, MISORDERS, LOST and JITTER shows the corresponding
statistics data for the data stream. The meanings of these are exactly as
defined in the SIP RFC.
RESTARTS is the number of times that a badly scrambled data stream
needed to be restarted (this is bad).
MISORDERS is the number of times that frames were received out of
order but, not lost (these frames generate poor signal quality, e.g. garbled
audio).
LOST is the number of frames which were not found in the data stream
(these frames generate poor signal quality if they reach a high volume).
JITTER is a measure of the timing of the frames (if the frame rate is 50fps
for the data stream, then a figure of 1ms corresponds to a 2% uncertainty
in the frequency of the audio signal).
Example VoIP Screen 5