Yealink SIP-T2 SERIES Administrator's Manual page 806

Administrator's Guide for SIP-T2 Series/T19(P) E2/T4 Series/CP860 IP Phones
If you enable the gatekeeper authentication, enter the desired value in the Gatekeeper
Username and Gatekeeper Password field respectively.
Click Confirm to accept the change.
6.
To configure local early media feature via web user interface:
Click Account->H.323.
1.
Select a desired value from the pull-down list of Local Early Media.
2.
Click Confirm to accept the change.
3.
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