Aastra 9000i Series Administrator's Manual page 439

Aastra Web UI
1 Click on Advanced Settings->Global SIP->Advanced SIP Settings.
2 Enter a value, in seconds, from 120 (2 min) to 3600 (1 hour) in the "BLF Subscription Period" field.
3 Click
5-162
to save your changes.
41-001343-01 Rev 02, Release 3.2.2