Audio Algorithm Support; Audio Algorithm Support Guidelines; Sip Encryption - Polycom RealPresence 1500 Administrator's Manual

Audio Algorithm Support

The Collaboration Server supports the following audio algorithms in AVC conferences: G.711, G.722,
G.722.1, G.722.1C, G.729A, G.719, G. 728, G.723.1 Polycom Siren 7 (in mono), Siren14, Siren 22 (in mono
or stereo) and SirenLPR.
Polycom's proprietary Siren 22 and industry standard G.719 audio algorithms are is supported for
participants connecting with Polycom endpoints.
The Siren 22 audio algorithm provides CD-quality audio for better clarity and less listener fatigue with audio
and visual communication applications. Siren 22 requires less computing power and has much lower
latency than alternative wideband audio technologies.
The SirenLPR audio algorithm provides CD-quality audio for better clarity and less listener fatigue with audio
and visual communication applications.
In SVC conferences, the system supports SAC (Scalable Audio Coding) audio algorithm.

Audio Algorithm Support Guidelines

● Siren 22 and G.719 are supported in both mono and stereo.
● Stereo is supported in H.323 calls only.
● Siren 22 is supported by Polycom HDX and Group series endpoints, version 2.0 and later.
● G.728 is supported in H.323, SIP and ISDN (Collaboration Server 1500/2000/4000) environments.
● SirenLPR is enabled by default and can be disabled by setting the system flag ENABLE_SIRENLPR,
to NO.
● SirenLPR is supported:
 In IP (H.323, SIP) calls only.
 In CP and VSW (Collaboration Server 1500/2000/4000) conferences.
 With Polycom CMAD and HDX 3.0.1 and later and Group series endpoints.
 For mono audio at audio line rates of 32Kbps, 48Kbps and 64Kbps.
 For stereo audio at audio line rates of 64Kbps, 96Kbps and 128Kbps.

SIP Encryption

The ENABLE_SIRENLPR_SIP_ENCRYPTION System Flag enables the SirenLPR audio algorithm when
using encryption with the SIP protocol.
The default value of this flag is NO meaning SirenLPR is disabled by default for SIP participants in an
encrypted conference. To enable SirenLPR the System Flag must be added to system.cfg and its value set
to YES.
Mono
The Siren 22, G.719 and SirenLPR mono audio algorithms are supported at the following bit rates.
Polycom®, Inc.
Additional Conferencing Information
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