The IllyVoIP app lets you review its Media security setting from the dialer settings. Use Follow line default when you want the app to use the current backend setting for the selected SIP line. Choose an override only when you know which mode your supported calling setup requires.
This guide covers the Android app controls in version 1.0.46, build 272. It describes the app setting, not a promise that every network segment or the other person’s telephone is encrypted. Only change it when no call is active or being set up.
1. Identify the line and its current setting
- Open the app dialer and check the current connection and line identity. If the wrong account is signed in, correct that before changing security settings.
- Open the dialer settings and find Encryption, then Media security.
- Read Backend default and Effective mode. Keep a note of the current selection before changing it.
The backend default is the line’s configured mode. The effective mode reflects what the app will use after applying its selection. A saved app override can therefore differ from the line default. Do not assume that changing the line in the Portal also removes an existing app override.
2. Choose the appropriate option
- Follow line default: use the backend choice for this line. This is the clearest option when you want the line configuration to remain the authority.
- Plain RTP: the unencrypted media option. It is not a secure replacement for an SRTP configuration that fails to connect.
- SRTP (SDES) and SRTP (DTLS): different supported secure-media modes. Choose the mode required by your verified setup; the two labels do not mean they can be substituted without checking compatibility.
Signaling security and media security are separate. A secure signaling connection does not, by itself, establish that the audio is encrypted. Likewise, selecting an SRTP option does not establish end-to-end encryption through every onward telephone network.
3. Apply the change while idle
- Finish any active call and wait until the dialer is idle. The app prevents this change during active calling.
- Select the intended mode. The app saves the local preference and refreshes its calling connection.
- Wait for the connection to become ready again. Reopen the setting and confirm the selected option and effective mode.
- For a planned call check, confirm both connection and two-way audio with an authorized test recipient. Normal service charges can apply.
A selected radio option is not a successful-call result. Treat a connection that is still starting or reporting an error as unresolved, even if the new preference has been saved. This setting does not change incoming-number destinations, caller-ID permissions or account credit.
Recover from an unsuccessful change
- Keep the exact error and the mode you selected. Do not repeatedly switch among modes while a call is attempting to connect.
- If you intended to follow the Portal configuration, return to Follow line default while idle and let the connection refresh.
- Check that the line itself is available and that your app is current. A suspended or otherwise unavailable line is not repaired by changing media security.
- If the problem persists, send Support the app version, selected mode, displayed backend default and effective mode, plus the time and call reference where available. Keep passwords and session data out of screenshots.
Does this change every device using the line?
No. The selection described here is the app’s local media preference. A line-wide configuration change in the Portal is a different action and can affect other devices. If your organization manages the line, agree on the intended mode before overriding it on an individual device.
Related guides
Reviewed 12 October 2026 against the current IllyVoIP controls, implementation and applicable references. Available options depend on account permissions and service state.