Question: Sometimes, when I open the Velox Prime app on my iPhone and dial out, the call does not go through. It seems the dialler is frozen and does not proceed to "Call Connected.". I check and there are no CDR records for my call. Logging-out and logging-back in fixes the issue. Why does this happen? How do I improve this?
Answer:
Unlike traditional mobile calls, VoIP depends on a few conditions being consistently met:
- Stable data connectivity (Wi-Fi or mobile data)
- An active SIP session (your app being registered/authenticated with the server)
- App state on the device (background activity, OS restrictions, or idle timeout)
Mobile VoIP apps don’t maintain a permanent connection. The app registers with the server (via SIP), but that registration has a validity period and can also be interrupted by:
- the phone moving between networks (WiFi ↔ mobile data, or moving locations)
- background app suspension by the OS
- NAT or carrier-level session timeouts
Quick troubleshooting:
- Logging out and back in (refreshes SIP authentication)
- Resetting network connectivity (forces reconnection path)
- In some cases, clearing the device registration server-side to re-establish a clean session (Request Velox Support to assist)
Other recommendations - on your iPhone:
- Allow Background App Refresh
- Go to Settings → General → Background App Refresh
- Ensure it’s turned ON (Wi-Fi & Mobile Data)
- Make sure the app is enabled in the list
- Disable Low Power Mode when using the app
- Settings → Battery → Low Power Mode → OFF
- This mode aggressively pauses background activity
- Ensure Mobile Data is allowed
- Settings → Mobile Data → [App] → ON
- Also enable Wi-Fi Assist if needed
- Keep notifications enabled
- Settings → Notifications → [App] → Allow Notifications
- This supports push-based re-registration
- Avoid force-closing the app
- Swiping the app away fully stops its connection
- Let it remain in the background instead