iOS 4 VOIP app responding in the background

Question

Hi there,

I have an iPhone VOIP app that copes with multi-multi transmit and receive (ie teleconferencing) set up using BSD sockets. I would like it to be able to respond to incoming requests when it is in the background but from what I can understand of the iOS 4 docs I can only do this on an NSStream object (or CFRead/WriteStream) by setting the property to NSStreamNetworkServiceTypeVoIP. This is a bit of a problem as my system is a UDP BSD sockets based application. Everything is received and sent on a single UDP socket.

Am I going to need to re-write my audio transmit/receive core to handle NSStreams or is there a way I can get iOS 4 to handle my BSD socket in a similar way to an NSStream? I assume this may be a problem as an NSStream is event based.

Would it be possible to detect when the application goes into the background and build a temporary NSStream object that will pass the data on to through the relevant handling and then continue as normal? Is it even possible to create a UDP NSStream?

Any ideas?

Answer 1

You can create a socket from a file descriptor with CFSocketCreateWithNative(), and then create a pair of streams with CFStreamCreatePairWithSocket(). It might let you use them on a UDP socket. Provided the streams don't read data unless you ask, you might be able to get away with using the FD directly.

Good luck with that though!