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Defines the audio transparency settings for SBC. SBC manages bandwidth for audio stream in the pass-through calls. Audio codecs that are unknown to the system are available to setup audio calls or streams.

SBC Core supports audio transparency in relaying unknown attributes and a subset of known attributes, such as rtpmap, fmtp, and T38 fax. The SBC also manages bandwidth for audio streams in pass-through calls. Audio transparency is controlled by the following PSP and Trunk Group parameters/flags.

Packet Service Profile:

• Enable transcoderFreeTransparency for the session (enable on either of the PSPs)

• Configure Audio Transparency settings

• Enable/disable Reserve BW For Preferred Audio Common Codec

SIP Trunk Group:

• Enable  Sdp Attribute Selective Relay on both ingress and egress Trunk Groups that receive the relayed SDP

See SBC SIP Transparency Implementation Guide for transparency implementation details.

Bandwidth (b) lines are transparently relayed and does not play any role in calculating the unknown audio codec bandwidth. The following PSP configuration bits for Audio Transparency feature are included for Unknown audio bandwidth reservation to calculate the Unknown audio bandwidth:

• Unknown Codec Packet Size

• Unknown Codec Bit Rate

To View and Edit Audio Transparency

On SBC main screen, go to All > Profiles > Media > Packet Service Profile >Audio Transparency.

Select the desired Packet Service Profile from the drop-down list to view the respective Audio Transparency parameters.

The Edit Audio Transparency window is displayed.

The following fields are displayed: