Http://www.dbltek.com VP-102 / VP-202 User Manual
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Mode 1: Use UDP packets and encryption.
Mode 2: Use UDP packets and encryption; use single UDP port.
Mode 3: Use TCP packets and encryption; Use single TCP port;
The mode 2 and mode 3 are the passive and the port use is assigned by the RELAY SERVER.
Note
: For Service providers, RELAY Proxy software is available at no charge. Please contact your
supplier for support. For end user, please contact your service provider to see if this feature is available.
2.4.3.3 Media Settings
Once a VoIP call is established, the Media channel is used for voice transmission. The settings listed below
configure the performance and operation of the Media channel.
1.
RTP Port (range)
– Audio stream is transmitted via Real Time Protocol (RTP) and at least 4 ports are used
per voice channel. The default port range is 16384 – 32768. Specify the port range depending on your
network environment if needed.
2.
Packet length (ms)
– This specify the length of a voice packet. The default packet length is 20 ms.
3.
Jitter Buffer Mode
–Three jitter modes are available. The
Fixed Mode
, which is the default mode, is a
simple first in first out mode, with a fixed jitter buffer delay. By definition the jitter buffer depth is twice
the jitter buffer delay. The
Sequential Mode
is also a fixed jitter buffer delay mode, but in this mode the
jitter buffer function looks at the packet timestamp for dropped or out of sequence packet problems. The
data packets are sorted based on the packet timestamp. The
Adaptive Mode
optimizes the size of the jitter
buffer delay and depth in response to network conditions, in addition to the sequential mode.
4.
Media QoS
– QoS is also available for Media packets to improve voice quality. This is rather significant
in a network environment with large amount of data traffics. Both
IP TOS
and
DiffServ
methods are
supported.
