7 acoustic echo cancellation (aec), 8 audio codecs – Polycom Version 1.4.x 17 User Manual
Page 52
Administrator Guide - SoundPoint
®
IP / SoundStation
®
IP
Features
44
Copyright © 2004 Polycom, Inc.
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:
Algorithm
MIME Type
Ref.
Bit Rate
Sample
Rate
Frame Size
Effective
audio band-
width
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.729AB
G729
RFC
1890
8 Kbps
8 Ksps
10ms - 80ms
3.5KHz
SID
CN
RFC
3389
N/A
N/A
N/A
N/A
RFC 2833
phone-event
RFC
2833
N/A
N/A
N/A
N/A
Central
(boot
server)
Configuration file:
ipmid.cfg
Specify codec priority, preferred payload sizes, and jitter
buffer tuning parameters.
For more information, see
•
4.6.1.6.1.1 Codec Preferences
page 79, and
•
4.6.1.6.1.2 Codec Profiles
Local
Web Server
(if enabled)
Specify codec priority, preferred payload sizes, and jitter
buffer tuning parameters.
Navigate to: http://
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
Interface
None.