The process described in the book establishes an ideal way to interconnect a legacy telephone system with WebRTC. We discussed interworking based on the SS7 IN setup as well as the IMS-based environment. We saw how PSTN gateways function with the help of MGW and SGW, which take care of media and signaling conversions, respectively. We listed a few challenges that can occur when an SIP network is made to function with the PSTN system; these challenges included address mapping and SIP-to-ISUP headers. We saw the approach to integrating call control logic with the WebRTC PSTN setup build so far.
After establishing the interconnectivity of a typical WebRTC ecosystem with all the other useful networks, we can now shift our focus to deliver a robust, feature-rich WebRTC application architecture, which will be discussed in the upcoming chapters.