This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The read-only property RTCIdentityErrorEvent.protocol is a DOMString describing the Idp protocol in use.
Firefox implements the interface of this property under the following name: RTCPeerConnectionIdentityErrorEvent. It is likely that it will correct this name when it will unprefix RTCPeerConnection, once spec and implementation will have been stabilized.
var protocol = event.protocol; event.protocol = "idp.html";
pc.onidpassertionerror = function( ev ) {
                           alert("The idp uses the following protocol '" + 
                                 ev.protocol + 
                                 ".");
                         } | Specification | Status | Comment | 
|---|---|---|
| WebRTC 1.0: Real-time Communication Between Browsers The definition of 'RTCIdentityErrorEvent.protocol' in that specification.  |  Candidate Recommendation | Initial specification. | 
| Desktop | ||||||
|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | |
| Basic support | No | ? | ? | No | Yes | ? | 
| Mobile | |||||||
|---|---|---|---|---|---|---|---|
| Android webview | Chrome for Android | Edge Mobile | Firefox for Android | Opera for Android | iOS Safari | Samsung Internet | |
| Basic support | No | No | ? | ? | ? | No | No | 
    © 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
    https://developer.mozilla.org/en-US/docs/Web/API/RTCIdentityErrorEvent/protocol