Hi everyone, today I've done a little research on the issue of incoming calls in the background on iOS. We're getting a lot of negative feedback since the introduction of iOS 7. | sometimes my app won't wake up after it goes to background, however, | sometimes it will. I get the impression, that it depends on the device. We have an iPhone 5 and an iPhone 5S where almost no call is signalled when the app is in the background, while another iPhone 5S and an iPhone 4S running the exact same app work as expected. All devices run iOS 7. There was a thread back in December on this list about background signalling (http://comments.gmane.org/gmane.comp.voip.pjsip/17912) but to be honest, I don't think the guys are on the right track. As far as I understood, the incoming INVITE is received on an already connected TCP socket, and PJSIP is marking that socket fine with kCFStreamNetworkServiceTypeVoIP. Maybe there is a misunderstanding on my side? Anyway, I was digging up good old printf-debugging and logging the socket descriptor that is marked as ServiceTypeVoIP (or the CFStream associated with that socket, to be correct) - i.e. in activesock_create_iphone_os_stream() in activesock.c. On the other hand I was printing the socket that the actual recv() is called on - i.e. in pj_sock_recv() in sock_bsd.c. They match. Always. Even on the devices the error is always reproducible with. In case the call is not signalled while the app is in the background, recv() is called right in the moment, the app is woken up by me bringing it into the foreground. Can anyone confirm that? Just as if iOS forgets that this is a socket marked for background VoIP operation... That together with the observation, that up to iOS 6 everything worked as expected, and the fact that calls in the background do work on some iOS 7 devices with the exact same app bundle, leads me to the assumption, that this might simply be a bug in iOS 7. I just wanted to check back with you guys before opening a bug report at Apple. Any thoughts? Did I miss something? Thanks, Sebastian.
