CDRs contain two sub-fields to convey the audio encoding values used for the codecs used on the ingress and egress legs. For pass-through calls, the most preferred codec in the SDP answer is logged in the CDR, for a transcoded call, the selected codec is logged in the CDR. The following table shows details for the sub-fields. See CDR Field Descriptions for the full list of additional media stream statistics sub-fields.

Audio Encoding Sub-fields in Additional Media Stream Statistics

Sub-field

Number

Sub-field Name

Max

length in

ASCII

TypeSTARTSTOPATTEMPTINTERMEDIATE
5ingress codecParams132CharacterNA256.5202.5NA
8egress codecParams132CharacterNA256.8202.8NA
 

The two sub-fields include the following information:

  • network type (P for packet, C for circuit)
  • codec type (numeric codec value, refer to Codec Type Descriptions)
  • mode-set/bit rate

For most codecs the data appears in the format <packet_type>:<codec_type>:<mode-set/bit rate>.  If more than one mode-set or bit rate value applies the values for the third component are separated by semi-colons.

 

For the EVS codec, only the primary mode rate is captured in CDRs and the following format applies for the sub-fields:

<packet_type>:<codec_type>:<bit-rate;mode set>

where bit-rate can be specified as a range (for example: 5.9-24.4) and mode set can contain multiple values separated by semi-colons (for example: 0-8).

 

For the SILK codec, the following format applies:

<packet_type>:<codec_type>:<maxaveragebitrate>

where maxaveragebitrate can be in the range 6000 to 40000.

Supported Codecs

The data applies to the following codecs/coding rates:

Codec Types and Coding Rates

(PSX) Codec SelectionsCoding Rate (Kbps)
AMR-Bandwidth EfficientVariable; mix of 4.75, 5.15, 5.90, 6.70, 7.40, 7.95, 10.20, 12.20
AMR-Octet AlignedSame for all AMR
EVRCB4.8, 5.8, 6.2, 6.6, 7.0, 7.5, 8.5, 9.3
EVRCB04.8, 5.8, 6.2, 6.6, 7.0, 7.5, 8.5, 9.3
EVS5.9, 7.2, 8, 9.6, 13.2, 16.4, 24.4, 32, 48, 64, 96, 128
G.72248, 56, 64
G.722 with Silence Suppression48, 56, 64
G.722.116, 24, 32
G.722.1 with Silence Suppression16, 24, 32
G.722.2 (AMRWB-Bandwidth Efficient)6.6, 8.85, 12.65, 14.25, 15.85, 18.25, 19.85, 23.05, or 23.85
G.722.2 (AMRWB-Octet Aligned)Same for all AMR-WB
G.723.15.3, 6.3
G.723.1A5.3, 6.3
iLBC13.3, 15.2
iLBC with Silence Suppression13.3, 15.2
Opus6 to 20
SILK8, 12, 16, 24
T.38 (version 0)up to 14.4
T.38 (version 3)33.6

Example

The CDR field numbers for Additional Media Stream Statistics for STOP and ATTEMPT records are 256 and 202 respectively. For example, when a CDR is decoded using a CAM Decoder, the Additional Media Stream Statistics field for the STOP record will have the following partial content:

256.1  Entries per stream                           "6
256.2  Number of streams                             01
256.3  ingress lostPktBursts1                        0
256.4  ingress lostPktSingles1                       0
256.5  ingress codecParams1                          P:27:4;8
256.6  egress lostPktBursts1                         0
256.7  egress lostPktSingles1                        0
256.8  egress codecParams1                           P:27:4;8"

Note

In the example, the first and the second columns are for illustration only, and not part of the actual decoded CDR.

The ";" (semicolon) character is used as a delimiter if more than one value applies.