Yealink SIP-T4X Administration Manual page 163

Administrator's Guide for SIP-T4X IP Phones
2. In the desired DSS key field, select Paging from the pull-down list of Type.
3. Enter the multicast IP address and port number in the Value field.
The valid multicast IP addresses range from 224.0.0.0 to 239.255.255.255.
4. Click Confirm to accept the change.
To configure a codec for multicast paging via web user interface:
1. Click on Features ->General Information.
2. Select the desired codec from the pull-down list of Multicast Codec.
3. Click Confirm to accept the change.
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