Polycom SIP 3.0.2 ユーザーズマニュアル

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 Configuring Your System
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Background Noise Suppression
Background noise suppression (BNS) is designed primarily for hands-free 
operation and reduces background noise to enhance communication in noisy 
environments.
There are no related configuration changes.
Comfort Noise Fill
Comfort noise fill is designed to help provide a consistent noise level to the 
remote user of a hands-free call. Fluctuations in perceived background noise 
levels are an undesirable side effect of the non-linear component of most AEC 
systems. This feature uses noise synthesis techniques to smooth out the noise 
level in the direction toward the remote user, providing a more natural call 
experience.
There are no related configuration changes.
Automatic Gain Control
Automatic Gain Control (AGC) is applicable to hands-free operation and is 
used to boost the transmit gain of the local talker in certain circumstances. This 
increases the effective user-phone radius and helps with the intelligibility of 
soft-talkers.
There are no related configuration changes.
IP Type-of-Service
The “type of service” field in an IP packet header consists of four 
type-of-service (TOS) bits and a 3-bit precedence field. Each TOS bit can be set 
to either 0 or 1. The precedence field can be set to a value from 0 through 7. The 
type of service can be configured specifically for RTP packets and call control 
packets, such as SIP signaling packets.
Configuration changes can performed centrally at the boot server or locally:
Central 
(boot server)
Configuration file: 
sip.cfg
Specify protocol-specific IP TOS settings.
For more information, refer to 
Local
Web Server
(if enabled)
Specify IP TOS settings. 
Navigate to: http://<phoneIPAddress>/netConf.htm#qo