To create or modify a Voice Codec Profile:
- In the WebUI, click the Settings tab.
- In the left navigation pane, go to Media > Media Profiles.
- From the Create Media Profile drop down box, select Voice Codec Profile.
Modifying a Voice Codec Profile
- Click the expand () Icon next to the entry you wish to modify.
- Edit the entry properties as required, see details below.
Creating a Voice Codec Profile
From the Create Media Profile drop down box at the top of the Media Profiles page, select Voice Codec Profile.
From the Codec drop down box, select a codec.
Configure the files and click OK. See field definitions below.
Create Voice Codec Profile
Voice Codec Profiles - Field Definitions
Parameter | Description |
---|
Description | |
Codec | Specifies the voice codec and encoding scheme used towards the IP side of a VoIP call. The selected codec affects the audio quality and bandwidth consumption of VoIP calls to which you apply the Voice Codec Profile (in the Media Profiles List). The codec choice depends on the interoperability requirements for connecting to other voice peers and bandwidth requirements. Most codecs use data compression algorithms, which saves bandwidth but slightly reduces the voice quality. G.711 does not use compression and requires more bandwidth. The following codecs are supported on Unable to show "metadata-from": No such page "_space_variables" platform:- G.711 A-Law
- G.711 u-Law
- G.722
- G.722.2
- G.723.1
- G.726
- G.729
- Opus
- SILK (see SILK Codec for more information)
. |
Bandwidth | Specifies the bandwidth frequency. This parameter has the following options: This parameter applies only to SILK. |
Rate | Specifies the voice sampling rate in bits/sec used by the codec. This parameter applies to G.722.2, G.723.1, G.729, Opus, and SILK codecs only. For all other codecs, the voice sampling rate is fixed and defined in the appropriate specification for that codec. |
Payload Size | The recommended length of time in milliseconds rounded up to the next full integer value represented by the media in a packet. Valid entry: 10, 20, 30, 40, 60, 80, 90 (specific codec determines values available). - Smaller payload sizes decrease audio transport latency at the expense of higher bandwidth consumption.
- Larger packet sizes reduce the bandwidth. The larger the payload size, the fewer and larger the packets. With larger payload sizes, fewer L2/Ethernet and IP/UDP/RTP headers are used; a disadvantage is that if UDP packets get lost, the impact on the voice quality is higher because a single packet contains more raw voice data.
SILK supports only the 20, 40, and 80 payload . For Re-Invite Only: If the SBC receives a larger than configured payload size from the peer offer in the re-invite, the SBC rejects with a 488 'Not Acceptable Here' response. The call rolls back to the previous negotiated offer answer. |
Payload Type | Specifies the payload type for profile. Applies to G722.2, G.726, Opus, and SILK codecs only. For SILK and Opus, the Payload Type option is 96 - 127. The default value is 120. |
Payload Format
| Specifies the mode for the payload: Bandwidth Efficient Mode or Octet Aligned Mode. Default entry: Bandwidth Efficient Mode. This setting applies to G.722.2 only. |
Voice Bit Rate | The maximum Opus bit rate (in bits/second) used for the current session. Valid entry: 0 (use variable bit rate) or 1 (use constant bit rate). Default entry: CBR. Parameter applies to Opus only. |
Use FEC | Specifies whether to use Forward Error Correction (FEC). Valid entry for Opus: 0 (do not use FEC) or 1 (use FEC). Default entry for Opus: 0. Valid entry for SILK: False (do not use FEC) or True (use FEC). Default entry for SILK: False. Parameter applies to Opus and SILK only.
|
Use DTX | Specifies whether to use Discontinuous Transmission (DTX). Valid entry for Opus: 0 (do not use DTX) or 1 (use DTX). Default entry for Opus: 0. Valid entry for SILK: False (do not use DTX) or True (use DTX). Default entry for SILK: False. Parameter applies to Opus and SILK only.
|
Complexity Level | Scales the complexity to optimize for CPU resources in real-time, which is mostly in trade-off to network bit rate. For the Unable to show "metadata-from": No such page "_space_variables" , the following options are available for this parameter: 0, 1, or 2. Default entry: 0.For the Unable to show "metadata-from": No such page "_space_variables" , the following option is available for this parameter: 0.This parameter applies only to SILK. |
SILK Codec
The
Unable to show "metadata-from": No such page "_space_variables"
and the
Unable to show "metadata-from": No such page "_space_variables"
the SILK audio codec. Skype designates SILK as an internet wideband audio codec for use in VoIP. SILK operates at two different sampling rates: 8000 Hz narrowband and 16,000 Hz wideband (see the
SILK Bandwith Options table). These rates allow for the capture of higher frequencies, which provide fuller sound, while also allowing interoperability with the Public Switched Telephone Network (PSTN). SILK has Low Bit Rate Redundancy (LBRR), also called Forward Error Correction (FEC), which protects the
Unable to show "metadata-from": No such page "_space_variables"
against packet loss.
The network bit rate of SILK is adaptive within the range that the following table specifies. The
Unable to show "metadata-from": No such page "_space_variables"
defines and modifies the average network bit rate in real-time, while the actual bit rate depends on the input signal and change over time. The bit rate can dynamically change within that range. Since all other parameters are equal, the bit rates result in higher audio quality.
Audio Bandwidth | Frequency (Hz) | Bit Rate (KBPS) | Description |
---|
Narrowband | 8000 | 6 - 20 | The Unable to show "metadata-from": No such page "_space_variables" only uses the narrowband mode either to interface to PSTN networks, or on low-end devices that support 8000 Hz or less sampling frequency. |
Wideband | 16,000 | 8 - 30 | The Unable to show "metadata-from": No such page "_space_variables" uses the wideband mode for all IP platforms that support 16,000 Hz or less sampling frequency. |
The following table outlines the
Unable to show "metadata-from": No such page "_space_variables"
SILK performance capacity.
SBC 1000/2000 SILK Performance Capacity
Configuration (post-Release 6.1.x) | Example SKU(s) | Number of DSPs | Number of Sessions, SILK NB <-> G.711 |
---|
Unable to show "metadata-from": No such page "_space_variables" , SIP entry model | SBC-1K-R-SIP-E | 1 | 14 |
Unable to show "metadata-from": No such page "_space_variables" , SIP | SBC-1K-R-SIP | 3 | 42 |
Unable to show "metadata-from": No such page "_space_variables" with PRI | SBC-1K-R-FXS8FXO-P, SBC-1K-R-P | 2 | 28 |
Unable to show "metadata-from": No such page "_space_variables" with FXx, no PRI | SBC-1K-R-FXSFXO, SBC-1K-R-FXS | 1 | 14 |
Unable to show "metadata-from": No such page "_space_variables" gateways | SBC-1K-R-4P-FXSFXO-GW | 1 | 14 |
Unable to show "metadata-from": No such page "_space_variables" , 1 DSP | SBC-2K-R-1 | 1 | 60 |
Unable to show "metadata-from": No such page "_space_variables" , 2 DSP | SBC-2K-R-2 | 2 | 120 |
Unable to show "metadata-from": No such page "_space_variables" , 4 DSP | SBC-2K-R-4 | 4 | 240 |
Unable to show "metadata-from": No such page "_space_variables" , 6 DSP | SBC-2K-R-6 | 6 | 360 |