what handler I can use to know the call has been answered by another device with the same extension
example:
1. 1001 calls to 1002
2. 1002 answered the call
3. on other devices using 1002 get notified that the phone has been answered



note : sorry if my english bad.

Hi Zame,
Thank you for your question.

Do you mean MDA (when several devices register with the same extension), not Call Pickup (when another user can answer call using another extension in the same Pickup group)?

When the call will be answered from MDA extension, the User will receive "Established" event:
https://www.devconnectprogram.com/site/global/products_resources/avaya_client_sdk/programming_docs/current/windows/communication/api_refs/html/E_Avaya_ClientServices_Call_Established.htm

You can check "Remote" property of the call and it will be true. It means that the User will be able only accept this call. Because the call has been accepted from related extension:
https://www.devconnectprogram.com/site/global/products_resources/avaya_client_sdk/programming_docs/current/windows/communication/api_refs/html/P_Avaya_ClientServices_Call_Remote.htm

i mean like this.

in step 3, i have tried CallFeatureService.CallPickupAlertStatusChanged and its not work, mybe i wrong.
in step 4, i have tried CallFeatureService.DirectedCallPickup but same its not work