AASTRA 6700i series, 9143, 9480i, 9480i CT SIP Administrator Guide EN - Manual (Page 483)

5-206 41-001343-01 Rev 03, Release 3.2.2
Aastra Web UI
1 For global configuration of BLA:
Click on Advanced Settings->Global SIP->Basic SIP Authentication Settings.
For per-line configuration of BLA:
Click on Advanced Settings->Line N (1-9).
In the "Line Mode" field, select the BLA option.
2 In the "Phone Number" field, enter the phone number of the IP phone.