 <p>The Reachability APIs will provide the connection change notifications to your app so that you can know when the connectivity changed from WWAN to wifi. It will not tell you if you've changed from Edge to 3G or LTE unfortunately. The Reachability API also has methods to test reachability to a specific host. So, in your app you can listen for the notifications that the connection method has changed, then when it does change test reachability to your target host and at that time make the decision whether to rebuild the session or leave it intact.</p>