Polycom Version 1.4.x 17 manual Acoustic Echo Cancellation AEC, Audio Codecs

Administrator Guide - SoundPoint® IP / SoundStation® IP Features

3.3.7 Acoustic Echo Cancellation (AEC)

The phone employs advanced acoustic echo cancellation for hands-free operation. Both linear and non-linear techniques are employed to aggressively reduce echo yet provide for natural full-duplex communication patterns.

3.3.8 Audio Codecs

The following table summarizes the phone’s audio codec support:

				Sample		Effective
						audio band-
Algorithm	MIME Type	Ref.	Bit Rate	Rate	Frame Size	width
G.711∝-law	PMCU	RFC	64 Kbps	8 Ksps	10ms - 80ms	3.5KHz
		1890
G.711a-law	PCMA	RFC	64 Kbps	8 Ksps	10ms - 80ms	3.5KHz
		1890
G.729AB	G729	RFC	8 Kbps	8 Ksps	10ms - 80ms	3.5KHz
		1890
SID	CN	RFC	N/A	N/A	N/A	N/A
		3389
RFC 2833	phone-event	RFC	N/A	N/A	N/A	N/A
		2833

	Configuration file:	Specify codec priority, preferred payload sizes, and jitter
Central	ipmid.cfg	buffer tuning parameters.
		For more information, see
(boot
server)		• 4.6.1.6.1.1 Codec Preferences <preferences/> on
		page 79, and
		• 4.6.1.6.1.2 Codec Profiles <profiles/> on page 79.
	Web Server	Specify codec priority, preferred payload sizes, and jitter
	(if enabled)	buffer tuning parameters.
		Navigate to: http://<phoneIPAddress>/coreConf.htm#au
Local		Changes are saved to local flash and backed up to <Ethernet
		address>-phone.cfg on the boot server. Changes will per-
		manently override global settings unless deleted via the
		Reset User Settings menu selection.
	Local Phone User	None.
	Interface

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