Codec Tieline ViA User Manual page 58

58 ViA User Manual v3
Packet Displays
Analysis
Loss Packets failed to
arrive.
Empty Indicates how
often the jitter
buffer 'reservoir'
empties causing
loss of audio.
Late The number of
packets that
arrive late and
after audio play
out.
FECd Indicates the
number of FEC
repaired packets
if FEC active.
Possible Causes
· LAN/WAN congestion
· Unreliable ISPs
· Unreliable networks
· Unreliable IP
hardware
· High number of
packets being lost or
arriving late
· Signal dropouts
using cell-phone
networks
· Renegotiation
causes the jitter
buffer reservoir to
empty
· Network congestion
· Jitter Buffer depth is
too low
· Packets have been
lost or corrupted over
the network
Possible Solutions
· Renegotiate connection bit rate
downwards
· If link quality good, add or increase
FEC as required
· Assess ISPs QoS if very bad
performance
· Once could be an anomaly –
assess lost & late packets
· If many lost packets and network is
unreliable – renegotiate bit rate
and /or FEC down
· If many late packets, increase jitter
buffer maximum and minimum
depth
· Auto-jitter buffer will adjust
automatically
· For manual jitter buffer settings,
increase jitter buffer depth 50-100
ms & reassess (if only a few
packets arrive late over time; audio
repairs will be automatic and may
not require buffer changes).
· Assess audio quality & the number
of FEC repairs – if many packets are
being 'lost', perhaps reduce FEC
&/or renegotiate bit rate down.
© Tieline Research Pty. Ltd. 2020