AAC Calls
Advanced Audio Coding-Low Delay (AAC-LD) is a super-wideband codec that provides excellent speech and music quality at various bit rates. The audio quality scales up with the bit rate. Two mutually incompatible RTP payload formats are supported: mpeg4-generic and MP4A-LATM.
For AAC-LD (mpeg4-generic) calls, the codec type (payload capability) value 42 is used.
For AAC-LD (MP4A-LATM) calls, a separate codec type value is used for each supported bit rate. The codec type values are 43 (128K), 44 (64K), 45 (56K), 46 (48K), 47 (32K), and 48 (24K).
The system adds an audio bandwidth field to the CDR for AAC-LD calls.
Field Names |
Definitions |
---|---|
origMediaCap_bandwidth |
This integer field contains the audio bandwidth. |
destMediaCap_bandwidth |
This integer field contains the audio bandwidth. |
The system populates the bandwidth fields based on the following table:
Codec |
Bandwidth |
---|---|
G711Alaw64k |
64 |
G711Alaw56k |
56 |
G711mu-law64k |
64 |
G711mu-law56k |
56 |
G722 64k |
64 |
G722 56k |
56 |
G722 48k |
48 |
G7231 |
7 |
G728 |
16 |
G729 |
8 |
G729AnnexA |
8 |
Is11172AudioCap |
0 |
Is13818AudioCap |
0 |
G729AnnexB |
8 |
G729AnnexAwAnnexB |
8 |
GSM Full Rate |
13 |
GSM Half Rate |
7 |
GSM Enhanced Full Rate |
13 |
Wideband 256K |
256 |
Data 64k |
64 |
Data 56k |
56 |
G7221 32K |
32 |
G7221 24K |
24 |
AAC-LD (mpeg4-generic) |
256 |
AAC-LD (MP4A-LATM) 128K |
128 |
AAC-LD (MP4A-LATM) 64K |
64 |
AAC-LD (MP4A-LATM) 56K |
56 |
AAC-LD (MP4A-LATM) 48K |
48 |
AAC-LD (MP4A-LATM) 32K |
32 |
AAC-LD (MP4A-LATM) 24K |
24 |
GSM |
13 |
iLBC |
15 or 13 |
iSAC |
32 |
XV150 MR 729A |
8 |
NSE VBD 729A |
8 |
AAC-LD (mpeg4-generic) Calls CDR Example
This example applies to a call with AAC-LD (mpeg4-generic) codec:
Field Names |
AAC CDR |
---|---|
globalCallID_callId |
121 |
origLegCallIdentifier |
101 |
destLegCallIdentifier |
102 |
callingPartyNumber |
51234 |
originalCalledPartyNumber |
57890 |
finalCalledPartyNumber |
57890 |
lastRedirectDn |
57890 |
origCause_Value |
0 |
dest_CauseValue |
16 |
origMediaCap_payloadCapability |
42 |
origMediaCap_Bandwidth |
256 |
destMediaCap_payloadCapability |
42 |
destMediaCap_Bandwidth |
256 |