Early Media; Early Media Configuration - Yealink SIP-T2 Series Administrator's Manual

Administrator's Guide for SIP-T2 Series/T4 Series/T5 Series/CP920 IP Phones

Early Media

The early media refers to the media (for example, audio and video) played to the caller before a SIP call is actually estab-
lished.
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 IP phones to resume and play the local ringback tone upon a subsequent 180
message received.
Topic

Early Media Configuration

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
It configures the time to wait for the IP phone to play the local ringback tone when the early media can-
Description
not be played.
-1-Do not play the local ringback tone
Permitted
0-Play the local ringback tone immediately
Values
1-100-Wait for a specified time to play the local ringback tone
Default 1
Parameter phone_setting.is_deal180
Description It enables or disables the IP phone to deal with the 180 SIP message received after the 183 SIP message.
0-Disabled
Permitted
1-Enabled, the IP phone will resume and play the local ringback tone upon a subsequent 180 message
Values
received.
Default 1
Web UI Features->General Information->180 Ring Workaround
Parameter phone_setting.change_183_to_180
Description It enables or disables the IP phone to handle the received second 183 message as the 180 message.
0-Disabled
Permitted
1-Enabled, the IP phone will play the early media first and play the local ringback tone when receiving the
Values
second 183 message.
Default 0
[1]
If you change this parameter, the IP phone will reboot to make the change take effect.
356
[1]
<y0000000000xx>.cfg
<y0000000000xx>.cfg
<y0000000000xx>.cfg