beautypg.com

Dtmf event rtp payload, Acoustic echo cancellation, Employs advance – Polycom SOUNDPOINT SIP 2.2.0 User Manual

Page 92: Conforms to rfc

background image

Administrator’s Guide SoundPoint IP / SoundStation IP

4 - 44

DTMF tones using the active voice codec or using RFC 2833 compatible

encoding. The coding format decision is based on the capabilities of the remote

end point.
Configuration changes can performed centrally at the boot server:

DTMF Event RTP Payload

The phone is compatible with RFC 2833 - RTP Payload for DTMF Digits,

Telephony Tones, and Telephony Signals. RFC 2833 describes a standard

RTP-compatible technique for conveying DTMF dialing and other telephony

events over an RTP media stream. The phone generates RFC 2833 (DTMF

only) events but does not regenerate, nor otherwise use, DTMF events

received from the remote end of the call.
Configuration changes can performed centrally at the boot server:

Acoustic Echo Cancellation

The phone employs advanced acoustic echo cancellation (AEC) for hands-free

operation. Both linear and non-linear techniques are employed to aggressively

reduce echo yet provide for natural full-duplex communication patterns.
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-34

,

Acoustic Echo Suppression

on page

A-41

, and

Background

Noise Suppression

on page

A-42

.

Central

(boot server)

Configuration file:
sip.cfg

Set the DTMF tone levels, autodialing on and off times, and other
parameters.

For more information, refer to

Dual Tone Multi-Frequency

on page

A-25

.

Central

(boot server)

Configuration file:
sip.cfg

Enable or disable RFC 2833 support in SDP offers and specify the
payload value to use in SDP offers.

For more information, refer to

Dual Tone Multi-Frequency

on page

A-25

.