Description
We are using WebRTC through MatrixSDK (MatrixSDK/JingleCallStack), which depends on JitsiWebRTC 124.0.1.
On iOS 18.4.1 and 26.x, we observe audio resume failures after GSM interruption when using CallKit.
Reproduction Scenario
Active WebRTC call (PeerConnection connected)
Incoming GSM call
GSM accepted
GSM ends
Return to WebRTC call
Observed Behavior
ICE remains connected
DTLS remains established
No renegotiation occurs
Call state remains connected
Audio device does not produce playout or capture
No crash
No fatal WebRTC errors
Logs show:
Failed to set stereo playout mode.
Failed to set stereo recording mode.
And earlier:
AVAudioSession activation failed: IsOtherAudioPlaying: true
After CallKit reactivation:
providerDidActivateAudioSession
WebRTC does not resume audio graph properly.
Environment
iOS: 18.4.1 / 26.x
Devices: iPhone 15 / 16 Pro
WebRTC: 124.0.1 (JitsiWebRTC)
MatrixSDK: 0.23.8.18
CallKit enabled
Audio session mode: .voiceChat
Category: .playAndRecord
Additional Testing
We manually tested with WebRTC M137 (137.0.0) by replacing the vendored WebRTC binary, and audio resume behavior appears improved.
Questions
Is WebRTC 124 known to have AVAudioSession resume issues on iOS 18+?
Has audio device handling changed in newer WebRTC versions for iOS 18 compatibility?
Is upgrading JitsiWebRTC recommended for CallKit-heavy VoIP applications on iOS 18+?
Description
We are using WebRTC through MatrixSDK (MatrixSDK/JingleCallStack), which depends on JitsiWebRTC 124.0.1.
On iOS 18.4.1 and 26.x, we observe audio resume failures after GSM interruption when using CallKit.
Reproduction Scenario
Active WebRTC call (PeerConnection connected)
Incoming GSM call
GSM accepted
GSM ends
Return to WebRTC call
Observed Behavior
ICE remains connected
DTLS remains established
No renegotiation occurs
Call state remains connected
Audio device does not produce playout or capture
No crash
No fatal WebRTC errors
Logs show:
Failed to set stereo playout mode.
Failed to set stereo recording mode.
And earlier:
AVAudioSession activation failed: IsOtherAudioPlaying: true
After CallKit reactivation:
providerDidActivateAudioSession
WebRTC does not resume audio graph properly.
Environment
iOS: 18.4.1 / 26.x
Devices: iPhone 15 / 16 Pro
WebRTC: 124.0.1 (JitsiWebRTC)
MatrixSDK: 0.23.8.18
CallKit enabled
Audio session mode: .voiceChat
Category: .playAndRecord
Additional Testing
We manually tested with WebRTC M137 (137.0.0) by replacing the vendored WebRTC binary, and audio resume behavior appears improved.
Questions
Is WebRTC 124 known to have AVAudioSession resume issues on iOS 18+?
Has audio device handling changed in newer WebRTC versions for iOS 18 compatibility?
Is upgrading JitsiWebRTC recommended for CallKit-heavy VoIP applications on iOS 18+?