Aastra Telecom SIP 57I - Manual (Page 257)

Operational Features
41-001160-00, Release 2.1, Rev 04 5-47
Configuring Operational Features
Operational IP Phone Features
Aastra Web UI
1 Click on Basic Settings->Preferences->General.
2 The "Stuttered Dial Tone" field is enabled by default. To disable this field, uncheck the box.
3 Click to save your changes.