It would have required much forethought to predict, in 2002, that realtime communications would be happening in the browser. Thus WebRTC was born. But a tragedy of WebRTC is that it is not by-default compatible with SIP. WebRTC authors could have specified SIP as the signaling protocol over websocket, but they left the spec open ended. I feel two ways about this: glad for choice, but disappointed that the choice most often made does not allow for interop with the "legacy" realtime communications protocol, SIP.