title: linphone-iphone in background-mod can't get an incoming call?
body: <p>I use linphone SDK in an iOS app.</p>
  
  <p>When app goes to background-mode, app some times can get an incoming call or push notifications message, some times not.</p>
  
  <p>Or if the app was in background-mode a few minutes ago, it can't get an incoming call.</p>
  
  <p>Please help me out.</p>
  
  <p>I used ipad to call the is in background-mode's iPhone.</p>
  
  <p>ipad's log:</p>
  
  <pre><code>linphone[2767:1066909] [Message] Garbage collecting unowned object of type LinphoneCallStats
  linphone[2767:1066909] [Message] Garbage collecting unowned object of type LinphoneCallStats
  linphone[2767:1066909] [Message] Garbage collecting unowned object of type LinphoneCallStats
  linphone[2767:1066909] [Message] Garbage collecting unowned object of type LinphoneCallStats
  linphone[2767:1066909] [Message] Garbage collecting unowned object of type LinphoneCallStats
  linphone[2767:1066909] [Message] Garbage collecting unowned object of type LinphoneCallStats
  linphone[2767:1066909] [Message] Garbage collecting unowned object of type LinphoneCallStats
  linphone[2767:1066909] [Message] Garbage collecting unowned object of type LinphoneCallStats
  </code></pre>
  
  <p>When I let the phone to the foreground can be dialed.</p>
  
  <pre><code>linphone[2767:1066909] [Message] Garbage collecting unowned object of type LinphoneCallStats
  linphone[2767:1066909] [Message] Garbage collecting unowned object of type LinphoneCallStats
  linphone[2767:1066909] [Message] Garbage collecting unowned object of type LinphoneCallStats
  linphone[2767:1066909] [Message] Background task belle-sip recv channel started. Unknown remaining time since application is not fully in background.
  linphone[2767:1066909] [Message] channel [0x10eb70000]: starting recv background task with id=[94].
  linphone[2767:1066909] [Message] channel [0x10eb70000]: received [437] new bytes from [TLS://sip.linphone.org:5223]:
  linphone[2767:1066909] [Message]    SIP/2.0 180 Ringing
  linphone[2767:1066909] [Message]    Via: SIP/2.0/TLS 192.168.1.232:58394;received=220.134.182.243;branch=z9hG4bK.5fJXlLPwC;rport=58394
  linphone[2767:1066909] [Message]    Record-Route: &lt;sips:37.59.51.72:5223;lr&gt;
  </code></pre>