Why would the Android connection manager or whatever stack is used permit an application to load the connection in such a way.
How to replicate:
1. Share short on instagram to story. 2. Watch as YouTube, Facebook and Instagram stop loading any videos or content. Browsers do not load pages.
Even when you are downloading in the fast direction, TCP sends ACK packets in the other direction, if the traffic in the slow direction overwhelms the slow path it will cause latency and/or packet loss for those ACK packets and cause the fast direction to become unusable.