title: Configuring iOS VoIP application to run in sleep/background mode
body: <p>I am developing a VoIP based iOS (7.1) application. It's underlying socket programming is written in C++ rather than objective C. The app runs fine in foreground but while putting in sleep/background mode it can't receive any communication from server.
  According to apple document we have to configure one of the app socket for VoIP usage. I am unable to figure out how to configure C++ sockets (Because there are many sockets; i.e. SSL, SIP, RESTful).</p>
  
  <p>The intention is to run the app in sleep mode until it's killed. Tried few links and even couple of them from SO, but since I am novice I would want to have a step by step procedure for this configuration. 
  [Note: In somewhere I found <strong>CoreFoudation framework</strong>, do I need to use that?]</p>