Hi

trunk incoming second call alert tones, digital telephone handset
I could not find.

Thank you very much for your help

If I understand correctly - second call is not ringing on phone?

You need at least two CALL buttons programmed on the phone (one for each line).

ok.
already have call buttons

When the second call comes in, but I want you to give warning tone to the handset.
This feature has IP phone.
Digital phone is it possible?

Make sure CFWD Busy is turned off.

Sounds like you need OFF HOOK RING, its set to 15 seconds in default.

thank you for your help

I do not support digital phone