This is a HN gem! Wonder how it didn't make it to first page. I once had a mobile app perform very poorly only for large downloads on a particular SSID. No oth

This is a HN gem! Wonder how it didn't make it to first page. I once had a mobile app perform very poorly only for large downloads on a particular SSID. No other applications had such issue. It turned out to be due to a firmware bug which scrapped TCP SACK field, but the problem manifested only for large data transfers over unreliable, high latency connections. Got us all chasing our tails for a while though...