Yealink T40G Administrator's Guide

Audio Features
379
Audio Codecs
CODEC is an abbreviation of COmpress-DECompress, capable of coding or decoding a digital data
stream or signal by implementing an algorithm. The object of the algorithm is to represent the
high-fidelity audio signal with minimum number of bits while retaining the quality. This can effectively
reduce the frame size and the bandwidth required for audio transmission.
The audio codec that the phone uses to establish a call should be supported by the SIP server. When
placing a call, the IP phone will offer the enabled audio codec list to the server and then use the audio
codec negotiated with the called party according to the priority.
Topics
Supported Audio Codecs
Audio Codecs Configuration
Supported Audio Codecs
The following table summarizes the supported audio codecs on IP phones:
Codec
Algorithm
Reference
Bit Rate
Sample
Rate
Packetization
Time
G722
G.722
RFC 3551
64 Kbps
16 Ksps
20ms
PCMA
G.711
a-law
RFC 3551
64 Kbps
8 Ksps
20ms
PCMU
G.711
u-law
RFC 3551
64 Kbps
8 Ksps
20ms
G729
G.729
RFC 3551
8 Kbps
8 Ksps
20ms
G726-16
G.726
RFC 3551
16 Kbps
8 Ksps
20ms
G726-24
G.726
RFC 3551
24 Kbps
8 Ksps
20ms
G726-32
G.726
RFC 3551
32 Kbps
8 Ksps
20ms
G726-40
G.726
RFC 3551
40 Kbps
8 Ksps
20ms
G723_53/
G723_63
G.723.1
RFC 3551
5.3 Kbps
6.3 Kbps
8 Ksps
30ms
iLBC_15_2kbps
iLBC
RFC 3952
15.2 Kbps
8 Ksps
20ms
iLBC_13_33kbps
iLBC
RFC 3952
13.33 Kbps
8 Ksps
30ms
opus
opus
RFC 6716
8-12 Kbps
16-20 Kbps
28-40 Kbps
48-64 Kbps
8 Ksps
12 Ksps
16 Ksps
24 Ksps
20ms

Yealink T40G Specifications

General

SIP Accounts	3
Wall Mountable	Yes
Opus Codec	No
Display	2.3 inch 132x64-pixel graphical LCD
Network	Dual-port Gigabit Ethernet
PoE	Yes
Headset Support	Yes, RJ9 port
Power Adapter	Optional
Voice Codecs	G.722, G.711(A/μ), G.729AB, G.726
Local Phonebook	1000 entries