Administrator's Guide for SIP-T2_Series_T4_Series IP Phones
4) (Optional.) Enter the DND off code in the DND Off Code field.
3.
Click Confirm to accept the change.
To specify the return code and the reason when DND is enabled via web user interface:
1.
Click on Features->General Information.
2.
Select the desired type from the pull-down list of Return Code When DND.
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