You can configure the distinctive ring tones via the phone’s Web UI.
Configuration as shown below:
When receiving an INVITE Message with Alert-info (Alert-Info: <http://127.0.0.1>; info=internal), the phone
will play the “Doing Doing” ringtone.
7.4.1.1 Alert-Info: Bellcore-drN
When the Alter-Info header contains the keyword “Bellcore-drN”, the IP phone will play the desired ring tone.
The following table identifies the corresponding ring tone: