Network connection lost while switching from phone call to app

Question

iOS app needs IVR phone call to complete verification. The user answers phone call and returns to app to continue. This was working fine earlier, but, recently started getting network connection lost error when user is switching from phone call to app. I am using standard NSURLSession functionality for service call. App uses Soap service to start the IVR call and give a success/fail response back. Error logs:

[connection] nw_read_request_report [C2] Receive failed with error "Software caused connection abort"

Task <91526D5A-BF88-416A-B035-9441BA6CC550>.<1> HTTP load failed, 1807/0 bytes (error code: -1005 [4:-4]) Task <91526D5A-BF88-416A-B035-9441BA6CC550>.<1> finished with error [-1005] Error Domain=NSURLErrorDomain Code=-1005 "The network connection was lost." UserInfo={_kCFStreamErrorCodeKey=-4, NSUnderlyingError=0x28086bd80 {Error Domain=kCFErrorDomainCFNetwork Code=-1005 "(null)" UserInfo={NSErrorPeerAddressKey=<CFData 0x282592670 [0x1ddd28660]>{length = 16, capacity = 16, bytes = 0x100201bbc7676c180000000000000000}, _kCFStreamErrorCodeKey=-4, _kCFStreamErrorDomainKey=4}}, _NSURLErrorFailingURLSessionTaskErrorKey=LocalDataTask <91526D5A-BF88-416A-B035-9441BA6CC550>.<1>, _NSURLErrorRelatedURLSessionTaskErrorKey=( "LocalDataTask <91526D5A-BF88-416A-B035-9441BA6CC550>.<1>" ), NSLocalizedDescription=The network connection was lost., NSErrorFailingURLStringKey=https://www.url?wsdl, NSErrorFailingURLKey=https://www.url?wsdl, _kCFStreamErrorDomainKey=4} The network connection was lost.

Tested this on iOS 13 and above. Seems like OS is disconnecting network connection for sometime and app fails to receive response of web service.

Answer 1

This worked in my case: In AppDelegate.

var backgroundUpdateTask: UIBackgroundTaskIdentifier = UIBackgroundTaskIdentifier(rawValue: 0)
func endBackgroundUpdateTask() {
    UIApplication.shared.endBackgroundTask(self.backgroundUpdateTask)
    self.backgroundUpdateTask = UIBackgroundTaskIdentifier.invalid
}
func applicationWillResignActive(_ application: UIApplication) {
    self.backgroundUpdateTask = UIApplication.shared.beginBackgroundTask(expirationHandler: {
        self.endBackgroundUpdateTask()
    })
}
func applicationDidBecomeActive(_ application: UIApplication) {
    self.endBackgroundUpdateTask()

}