We are using a Google WebRTC library to develop native apps both in Android and in iOS.
For iOS we are using https://cocoapods.org/pods/GoogleWebRTC GoogleWebRTC 1.1.23765
For Android we use https://bintray.com/google/webrtc/google-webrtc#files/org%2Fwebrtc%2Fgoogle-webrtc%2F1.0.19742
We get an error on the iOS version upon establishing the RemoteDescription on the SDP sent from XMS. The Android version works fine.
This is just to ask if you have any knowledge of interoperability issues between XMS and this WebRTC library in it's iOS incarnation.
I don't know if your issue is related to profile-level-id attribute set in XMS. We had a customer reporting this few weeks ago. You can disable H264 video codec in your SDP offer to XMS. If this error disappears, it is likely due to the profile-level-id.
I have been working with Max on a case that he opened with the support team. In the testing it does seem to be related to the profile level. I will post up additional findings for the community once we have closed on that services ticket