Administrator Guide - SoundPoint
®
IP / SoundStation
®
IP
Features
48
Copyright © 2005 Polycom, Inc.
3.3.3 Local Conference Mixing
The phone’s audio processing subsystem contains a flexible three-party conferencing
capability
4
. This feature can be used to set up local three-party conferences where no
external protocol signaling is involved.
3.3.4 Voice Activity Detection (VAD)
The purpose of VAD is to conserve network bandwidth by detecting periods of rela-
tive “silence” in the transmit data path and replacing that silence efficiently with spe-
cial packets that indicate silence is occurring. For those compression algorithms
without an inherent VAD function, such as G.711, the phone is compatible with the
comprehensive codec-independent comfort noise transmission algorithm specified in
RFC 3389. This algorithm is derived from G.711 Appendix II, which defines a com-
fort noise (CN) payload format (or bit-stream) for G.711 use in packet-based, multi-
media communication systems. The phone generates CN packets (also known as
Silence Insertion Descriptor (SID) frames) and also decodes CN packets, efficiently
regenerating a facsimile of the background noise at the remote end.
Central
(boot
server)
Configuration file:
sip.cfg
Set the jitter buffer tuning parameters including minimum
and maximum size and shrink aggression.
•
For more information, see 4.6.1.8.1.2 Codec Profiles
<profiles/> on page 93.
Local
Web Server
(if enabled)
Set the jitter buffer tuning parameters including minimum
and maximum size and shrink aggression.
Navigate to: http://<phoneIPAddress>/coreConf.htm#au
Changes are saved to local flash and backed up to <
Ethernet
address
>-phone.cfg on the boot server. Changes will per-
manently override global settings unless deleted via the
Reset User Settings menu selection.
Local Phone User
Interface
None.
4. On SoundStation IP
®
4000, conferences are not available if the G.729 codec is enabled on the phone.
This restriction will be removed in future releases.
Central
(boot
server)
Configuration file:
sip.cfg
Enable or disable VAD and set the detection threshold.
•
For more information, see 4.6.1.8.10 Voice Activity
Detection <VAD/> on page 102.
Содержание SoundPoint IP 500
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Страница 148: ...Administrator Guide SoundPoint IP SoundStation IP Optimization 140 Copyright 2005 Polycom Inc ...
Страница 158: ...Administrator Guide SoundPoint IP SoundStation IP Session Initiation Protocol SIP 150 Copyright 2005 Polycom Inc ...
Страница 162: ...Administrator Guide SoundPoint IP SoundStation IP Appendix 1 154 Copyright 2005 Polycom Inc ...