I actually believe the PSTN is so ingrained in international networks that it will be around for another 50 years, minimum. Think SS7 and the fact that anything

I actually believe the PSTN is so ingrained in international networks that it will be around for another 50 years, minimum. Think SS7 and the fact that anything that touches PSTN relies on a legacy implementation at some point (probably all VoIP terminates there at some point, every cellular device, etc.). This is just a guess though on my part..