Built not to take you off air

What happens when

• A phone moves from Wi-Fi to 4G

  The app picks up the same session on the new network, rather than joining again. A line locked open stays open.

  Measured Arriving on Wi-Fi: under half a second of silence. Leaving it: 3.5–4.2 s. On an Android 15 emulator — a real phone clings to fading Wi-Fi first, so expect longer.

• The connection drops

  The panel dims and says RECONNECTING, with a double beep and a buzz every 8 seconds until it is back, and one higher tone when it is. It rejoins by itself; a line that was locked open comes back closed, the safe way round.

  Measured The warning is up 0.1 s after the server goes, in a browser.

• A device vanishes

  Its account is held for about 20 seconds, then freed. Leaving, or closing the page, frees it at once.

  Measured 20.1 s for a browser, 21.3 s for the iPhone app.

• Someone signs in on a second device

  The second device is refused, and told which device and group the account is on air in: two devices never fight over one person. A phone back from a tunnel cannot take the account back from the device that replaced it.

• The venue network changesON Comms Server

  Once the change has held for 10 seconds, the server moves its audio to the new addresses — at most once a minute — and announces itself on the network again.

• The server stops answeringON Comms Server

  The Mac and Windows apps ask it every 10 seconds; after six unanswered it is stopped and started again. A crash restarts it after a growing pause, never in a tight loop.

  Measured A frozen server replaced 75 s after it stopped answering.

• The venue has no internetON Comms Server

  Everyone on the venue network keeps talking. The licence runs for 30 days without checking in.

• The switcher goes quiet

  Every camera it feeds reads NO TALLY. A camera nobody has heard about reads unknown, never “off” — a wrong colour is worse than none.

• It is plugged into a truck network

  Nothing floods it: no broadcast or multicast but Bonjour’s own announcements, every retry with a floor and a cap, and TSL tally only listens.

  Tested Every part run against stand-ins, with anything sent off the computer refused, 25 September 2026.

• The computer wants to sleep

  ON Comms Server, ON Comms Tally and ON Comms Bridge keep the computer awake while they work.

• An update arrives mid-showON Comms Server

  It installs only when an admin chooses. On Windows it does not even download one while anyone is on air.