Administrator’s Guide for SIP-T2 Series/T4 Series/T5 Series/CP920 IP Phones
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Codec
Packetization Time (Minimum)
Packetization Time (Maximum)
opus
10ms
20ms
iLBC_15_2kpbs
20ms, 40ms, 60ms
iLBC_13_33kpbs
30ms, 60ms
PTime Configuration
The following table lists the parameter you can use to configure the PTime.
Parameter account.X.ptime
[1]
<MAC>.cfg
Description It configures the ptime (in milliseconds) for the codec.
Permitted
Values
0-Disabled
10-10
20-20
30-30
40-40
50-50
60-60
Default
20
Web UI
Account > Advanced > PTime (ms)
[1]
X is the account ID. For T57W/T54W/T48U/T48S/T48G/T46U/T46S/T46G/T29G, X=1-16; for
T53W/T53/T43U/T42G/T42U/T42S, X=1-12; for T41P/T41S/T27G, X=1-6; for T40P/T40G/T23P/T23G, X=1-3; for T21
(P) E2, X=1-2; for T19(P) E2/CP920, X=1.
Early Media
The early media refers to the media (for example, audio and video) played to the caller before a SIP call is actually
established.
Current implementation supports early media through the 183 message. When the caller receives a 183 message
with SDP before the call is established, a media channel is established. This channel is used to provide the early
media stream for the caller.
You can also configure 180 ring workaround which defines whether to deal with the 180 message received after
the 183 message. When the caller receives a 183 message, it suppresses any local ringback tone and begins to
play the media received. 180 ring workaround allows the phones to resume and play the local ringback tone upon
a subsequent 180 message received.
Topic
Early Media Configuration
The following table lists the parameters you can use to configure the early media.
Parameter phone_setting.early_media.rtp_sniffer.timeout
[1]
<y0000000000xx>.cfg
