For a past few days, I have been exploring control Filter and data filter. I am unable to understand how control moves from various functions of data filter to control Filter. One thing that I am unable to figure out is that when I pass verdict as .allow in dataFilter's handleNewFlow and mark .shouldReport as true, I get inBytes and outbytes in the flow report of handle() in controlFilter. But when I pass verdict as needRules and wait till the handle is called in controlFilter when the report.event == .flowClosed, I don't get inBytes and outBytes. I am unable to understand this complete flow of network extension from the apple documentation. Can someone provide me with some flow chart or some pictorial representation or detailed explanation of network extension for iOS? Also is there some way to imitate the ..statisticsReportFrequency for iOS as it is not available for iOS?