AudioCodes Mediant 4000 SBC User Manual page 652

CHAPTER 28 Advanced SBC Features
■ Smart Transcoding: If the SBC (Enterprise or Access SBC) detects WAN network
impairments during a call between the Enterprise SBC and Access SBC, the SBC employs
voice transcoding by switching the coder from G.711 to Opus for that specific call only.
Transcoding is done only on the path between the Enterprise SBC and Access SBC. As Smart
Transcoding is applied only on a per call basis, it preserves valuable DSP resources that may
be required for other functionalities. An advantage of using the Opus coder is that it consumes
less bandwidth than G.711 and overcomes packet loss (by dynamic packet redundancy),
allowing the SBC to support more concurrent calls than with G.711 for the same bandwidth.
This mode is useful for WAN networks that are relatively stable, allowing the use of G.711
whenever possible and switching to Opus only during adverse network conditions.
Configuration of the Enterprise SBC:
● Device's License Key includes the SBC transcoding feature
● Coder Groups table:
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● Allowed Audio Coders Groups table:
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● IP Profiles table - main IP Profile:
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● IP Profiles table - alternative IP Profile:
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● Quality of Service Rules table (see
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Configuration of the Access SBC for both Smart Transcoding and Managed Opus is listed below.
(For Managed G.729, configuration is the same as the Enterprise SBC.)
■ Coder Groups table:
● Coders Group with G.711 and Opus
● Coders Group with Opus
■ Allowed Audio Coders Group table: Allowed Audio Coders Group with Opus
Coders Group with G.711
Coders Group with Opus
Allowed Audio Coders Group with G.711
Allowed Audio Coders Group with Opus
'Extension Coders Group': Select the Coders Group with G.711
'Allowed Audio Coders': Select the Allowed Audio Coders Group with G.711
'Allowed Coders Mode': Restriction
'RTCP Feedback': Feedback On
'Voice Quality Enhancement': Enable
'Extension Coders Group': Select the Coders Group with Opus
'Allowed Audio Coders': Select the Allowed Audio Coders Group with Opus
'Allowed Coders Mode': Restriction
'RTP Redundancy Mode': Enable
'RTCP Feedback': Feedback On
'Voice Quality Enhancement': Enable
'Max Opus Bandwidth': 80000
'Rule Metric': Poor InVoice Quality
'Alternative IP Profile Name': name of Alternative IP Profile (above)
Configuring Quality of Service
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Mediant 4000 SBC | User's Manual
Rules):