Hi all. I have just started building a soft phone using pjsua. Unfortunately, I haven't understood it much. I don't know when the function "on_call_state()" in PjsuaClient.java is called ? Can anyone explain for me? Thanks in advance. -- ======================================================================= Best regards and thanks. Vu Ngoc Kha R&D Department - Software Center - Viettel Telecom 5th Floor - The Pacific Ocean Building - 93B - Trung Kinh Street - Cau Giay District - Ha Noi - Viet Nam Mobile Phone: +84-91-5916218 ; +84-98-9353284 Home Phone: +84-36-2-478535 Email: ngockhavu@gmail.com