Polycom SIP 3.1 - Manual (Page 130)

Administrator’s Guide SoundPoint IP / SoundStation IP
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 Acoustic Echo Cancellation on page
A-37 , Acoustic Echo Suppression on page A-46 , and Background
Noise Suppression on page A-47 .
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.
Audio Codecs
The following table summarizes the phone’s audio codec support:
Note AEC on the SoundPoint IP 301 handset is not supported.
Algorithm MIME Type Ref. Bit Rate
Sample
Rate
Frame Size
Effective
audio
bandwidth
G.711
μ-law
PMCU RFC 1890 64 Kbps 8 Ksps 10ms - 80ms 3.5KHz
G.711a-law PCMA RFC 1890 64 Kbps 8 Ksps 10ms - 80ms 3.5KHz
G.722 G722/8000 RFC 1890 64 Kbps 16 Ksps 10ms - 80ms 7 KHz
G.722.1 G7221/16000 RFC 3047 16 Kbps,
24 Kbps,
32 Kbps 16 Ksps 20ms - 80ms 7 KHz
G.722.1C G7221/
32000 G7221C 24 Kbps
32 Kbps
48 Kbps 32 Ksps 20ms - 80ms 14 KHz
G.729AB G729 RFC 1890 8 Kbps 8 Ksps 10ms - 80ms 3.5KHz
SID CN RFC 3389 N/A N/A N/A N/A
Lin16 L16/16000
L16/32000
L16/48000 RFC 1890 25.6 Kbps
51.2 Kbps
76.8 Kbps 16 Ksps
32 Ksps
48 Ksps 10ms 7 KHz
14 KHz
22 KHz