Hi //////// I'll correct the line breaks and repost it. //////// Thank you for your response. I am sorry. my before descrption was incorrect. myApp is executing following sequence. But iPhone sometimes doesn't call didActivateAudioSession of step6 after this sequence. (I said "sometimes", but once it occurs, it will occur repeatedly) How about this sequence? If you have some notice about it, could you tell me it? myApp --- AVAudioSession setCategory: AVAudioSessionCategoryPlayAndRecord --->iOS myApp <-- return YES ---- iOS myApp --- AVAudioSession setMode: AVAudioSessionModeVoiceChat --->iOS myApp <-- return YES ---- iOS myApp --- AVAudioSession setActive:YES --->iOS myApp <-- return YES ---- iOS myApp --- CXStartCallAction --->iOS myApp <-- performStartCallAction callback --- iOS myApp <-- didActivateAudioSession callback ----iOS

Hi Thank you for your response. I am sorry. my before descrption was incorrect. myApp is executing following sequence. But iPhone sometimes doesn't call didActivateAudioSession of step6 after this sequence. (I said "sometimes", but once it occurs, it will occur repeatedly) How about this sequence? If you have some notice about it, could you tell me it? myApp --- AVAudioSession setCategory: AVAudioSessionCategoryPlayAndRecord --->iOS myApp <-- return YES ---- iOS myApp --- AVAudioSession setMode: AVAudioSessionModeVoiceChat --->iOS myApp <-- return YES ---- iOS myApp --- AVAudioSession setActive:YES --->iOS myApp <-- return YES ---- iOS myApp --- CXStartCallAction --->iOS myApp <-- performStartCallAction callback --- iOS myApp <-- didActivateAudioSession callback ----iOS