The present invention provides a system and method for real-time communication signaling between HTML5 endpoints and the IMS Core of a telecommunication network. The system includes a WebRTC Session Controller (WSC) that terminates Web communications with the client-side, parses, and normalizes the Web communications into an internal protocol suitable for communication with telecommunications network systems. The client-side controller provides a JavaScript API which encapsulates the signaling aspect of a communication session of the HTML5 application, including gathering media description, establishing signaling channels, and exchanging media descriptions with the WSC, populating the relevant WebRTC objects, managing the call after it has been established. The JavaScript API, which is more flexible than widgets that provide rigid capabilities, thereby simplifies development and implementation of real-time communication Web applications, enabling the developers to concentrate on the business logic implementation and innovate on user interface designs.