Hi, All I am making VOIP-based APP using linphone library(3.3.0) on Android(4.4). The APP is designed to have a feature of dialing the real phone call. when the call is established , the phone can send dtmf message to the APP by tapping key. Currently ,the app doesn't always receives all of dtmf messages. With the help of wireshark , I really catch all of dtmf message from real phone call . Would you please help to enlighten me to debug this issue? Thanks a lot .