Compression - H3C MSR 20-20 Command Reference Manual

2559
generated, the toneless intervals will make both parties in conversation feel
uncomfortable.
Related command: line and vad-on.
Example # Disable comfortable noise function on subscriber line 1/0.
<Sysname> system-view
[Sysname] voice-setup
[Sysname-voice] subscriber-line 1/0
[Sysname-voice-line1/0] undo cng-on

compression

Syntax
compression { 1st-level | 2nd-level | 3rd-level | 4th-level } { g711alaw | g711ulaw |
g723r53 | g723r63 | g726r16 | g726r24 | g726r32 | g726r40 | g729a | g729r8 }
undo compression { 1st-level | 2nd-level | 3rd-level | 4th-level }
View POTS/VoIP/VoFR entity view
Parameter 1st-level: Specifies a codec with the first priority.
2nd-level: Specifies a codec with the second priority.
3rd-level: Specifies a codec with the third priority.
4th-level: Specifies a codec with the fourth priority (namely, the lowest priority).
g711alaw: G.711 A-law codec (defining the pulse code modulation technology),
requiring a bandwidth of 64 kbps, usually adopted in Europe.
g711ulaw: G.711μ-law codec, requiring a bandwidth of 64 kbps, usually adopted
in North America and Japan.
g723r53: G.723.1 Annex A codec, requiring a bandwidth of 5.3 kbps.
g723r63: G.723.1 Annex A codec, requiring a bandwidth of 6.3 kbps.
g726r16: G.726 Annex A codec. It uses the adaptive differential pulse code
modulation (ADPCM) technology, requiring a bandwidth of 16 kbps.
g726r24: G.726 Annex A codec. It uses ADPCM, requiring a bandwidth of 24
kbps. The support for the g726r24 keyword varies with devices.
g726r32: G.726 Annex A codec. It uses ADPCM, requiring a bandwidth of 32
kbps. The support for the g726r32 keyword varies with devices.
g726r40: G.726 Annex A codec. It uses ADPCM, requiring a bandwidth of 40
kbps. The support for the g726r40 keyword varies with devices.
g729a: G.729 Annex A codec (a simplified version of G.729), requiring a
bandwidth of 8 kbps.