I'm developing an iOS app that aims to manage network usage on an iPhone acting as a Personal Hotspot. I'd like to know whether there is a supported public API that allows a third-party iOS app running on the host iPhone to limit the download speed of devices connected through Personal Hotspot. For example, I'd like to limit the download speed of tethered devices to a maximum of 1 Mbps, without limiting the host iPhone's own network traffic. Is this technically possible using public iOS APIs, or is this type of bandwidth control restricted to the system? Thank you for your guidance.

I am developing a consumer iOS app for App Store distribution and would like to confirm the appropriate public API for the following use case. The app needs to measure the amount of network traffic passing through the device over short time intervals, for example once per second or more frequently. The app does not need to inspect packet contents, block or filter traffic, or provide a remote VPN service. It also should not generate dedicated network traffic solely for speed measurement. The goal is only to observe device-wide network traffic volume and convert that information into a simple real-time indicator for the user. I am currently investigating the Network Extension framework. Would NEPacketTunnelProvider be an appropriate API for this use case? If not, is there another supported Network Extension provider or other public iOS API intended for measuring device-wide network traffic in this manner? I would like to choose an architecture that is technically supported by Apple and appropriate for a consumer app distributed through the App Store before beginning implementation.