If you dont immediately prompt the user that a network error has happened, you are sacrificing the perception of the app for the network. You are delaying a conclusion for the user. That the network is not working. Someone from the help desk will call you some day and will tell you he has users that are looking at progresbars or empty screens. And you will do some digging and you will see the app is retrying 3 times and there is a 12 second timeout on each request. User will not even stay on that screen for that long! It will then hit you how appropriate is after one timed out request to promt the user with an informative message and have him click retry if he wants to. The perception that some request fails just once rarely is false. Some people may work in a building that has a poor router. Or go to a bar that has a poor or crowded router and hang around. 3 out of 5 requests may consistently time out in that place indefinitely. IMHO Inform the user fast a request has failed and dont test his patience. This may get them upset! He wont be upset to manually retry with one tap.