Yealink SIP-T48G Administrator's Manual page 706

Administrator's Guide for SIP-T2 Series/T19(P) E2/T4 Series/CP860 IP Phones
Codec
G726-16
G726-24
G726-32
G726-40
G723_53/
G723_63
iLBC
Packetization Time
Ptime (Packetization Time) is a measurement of the duration (in milliseconds) of the
audio data in each RTP packet sent to the destination, and defines how much network
bandwidth is used for the RTP stream transfer. Before establishing a conversation, codec
and ptime are negotiated through SIP signaling. The valid values of ptime range from
10 to 60, in increments of 10 milliseconds. The default ptime is 20ms. You can also
disable the ptime negotiation.
Codecs and priorities of these codecs are configurable on a per-line basis. The attribute
"rtpmap" is used to define a mapping from RTP payload codes to a codec, clock rate
and other encoding parameters.
The corresponding attributes of the codec are listed as follows:
Codec Configuration Methods
G722
PCMU
PCMA
G729
G723_53
G723_63
686
Algorithm Reference
G.726 RFC 3551
G.726 RFC 3551
G.726 RFC 3551
G.726 RFC 3551
G.723.1 RFC 3551
iLBC RFC 3952
Configuration Files
Web User Interface
Configuration Files
Web User Interface
Configuration Files
Web User Interface
Configuration Files
Web User Interface
Configuration Files
Web User Interface
Configuration Files
Web User Interface
Bit Rate Sample
Rate
16 Kbps 8 Ksps
24 Kbps 8 Ksps
32 Kbps 8 Ksps
40 Kbps 8 Ksps
5.3kbps
8 Ksps
6.3kbps
13.33 Kbps
8 Ksps
15.2 Kbps
Priority
1
2
3
4
0
0
Packetization
Time
20ms
20ms
20ms
20ms
30ms
20ms
30ms
RTPmap
9
0
8
18
4
4