Patton electronic SmartNode 4110 Series IP Phone User Manual


 
VoIP profile configuration task list 582
SmartWare Software Configuration Guide 47 • VoIP profile configuration
The operating modes for the dejitter buffer are illustrated in figure 4:
Adaptive—The adaptive buffer automatically adapts to variations in the network’s delay characteristics and
in general yields the best results for voice conversations.
Static—The static buffer is useful for voice conversations if you have specific information about your net-
work’s delay characteristics (such as jitter period, etc.), so it should only be used by experienced users.
Static-data—The static-data mode if you want to create a profile for fax or modem transmission without
using the T.38 or fax bypass features described later in this chapter
Figure 4. Adaptive versus static dejitter buffer
Procedure: Configure the dejitter buffer.
In the adaptive dejitter buffer there are parameters that can be
configured (such as shrink-speed, grow-step, etc.) that should not
be changed unless it is necessary to do so. An incorrect configura-
tion can lead to interoperability problems and loss of service.
Therefore, it is strongly recommended that only expe-
rienced users change these parameters.
IMPORTANT
Adaptive Fixed
max delay => max fill level
Adaptive algorithm resizes
buffersize up to max delay,
depending on network traffic !
voice packets
max delay => buffersize
Fixed algorithm sets buffersize to max delay.
Generally mean delay of voice packets is
max delay / 2
voice packets
mean delay = max delay / 2