Audio Codecs - Polycom 1725-11530-310 Administrator's Manual

Administrator's Guide SoundPoint IP / SoundStation IP
Note

Audio Codecs

Algorithm MIME Type
G.711μ-law PMCU
G.711a-law PCMA
G.722 G722/8000
G.722.1 G7221/16000
G.722.1C G7221/
32000
G.729AB G729
SID CN
Lin16 L16/16000
L16/32000
L16/48000
4 - 76
When using the handset on any SoundPoint IP phones, AEC is not normally
required. In certain situations, where echo is experienced by the far-end party,
when the user is on the handset, AEC may be enabled to reduce/avoid this
echo. To achieve this, make the following changes in the sip.cfg configuration
file (default settings for these parameters are disabled):
voice.aec.hs.enable = 1
voice.aes.hs.enable = 1
voice.ns.hs.enable = 1
voice.ns.hs.signalAttn = -6
voice.ns.hs.silenceAttn = -9
For more information, refer to
A-37, Acoustic Echo Suppression <aes/>
Noise Suppression <ns/>
For the SoundPoint IP 501 and 601, utilizing acoustic echo cancellation will
introduce a small delay increase into the audio path which might cause a lower
voice quality.
AEC on the SoundPoint IP 301 handset is not supported.
The following table summarizes the phone's audio codec support:
Ref. Bit Rate
RFC 1890 64 Kbps
RFC 1890 64 Kbps
RFC 1890 64 Kbps
RFC 3047 16 Kbps,
24 Kbps,
32 Kbps
G7221C 24 Kbps
32 Kbps
48 Kbps
RFC 1890 8 Kbps
RFC 3389 N/A
RFC 1890 25.6 Kbps
51.2 Kbps
76.8 Kbps
Acoustic Echo Cancellation <aec/>
on page A-46, and
on page A-47.
Sample
Rate Frame Size
8 Ksps 10ms - 80ms
8 Ksps 10ms - 80ms
16 Ksps 10ms - 80ms
16 Ksps 20ms - 80ms
32 Ksps 20ms - 80ms
8 Ksps 10ms - 80ms
N/A N/A
16 Ksps 10ms
32 Ksps
48 Ksps
on page
Background
Effective
audio
bandwidth
3.5KHz
3.5KHz
7 KHz
7 KHz
14 KHz
3.5KHz
N/A
7 KHz
14 KHz
22 KHz