Networking and Firewall Issues
Tuple: API Backend
Make sure that you can access production.tuple.app, from which we serve the API for authentication and to populate lists of your contacts.
Twilio's Network Traversal Service (NTS): TURN Relay Servers
When it's not possible to obtain a peer-to-peer connection through local or public networks, Tuple uses Twilio to route media data through TURN servers.
Tuple uses Ably to facilitate the initiation of calls between peers and to provide availability (active/inactive/busy) status updates to clients.
If you're having issues with the list of available users, see this support article about whitelisting.