Resumen
The confrontation of these two technologies - packet-switching and circuit-switching ? has a long history, and it seems to be incessant. It had started with Asynchronous Transfer Mode technology in the 1990s. The breakup of the Bell System marked a key loss in Bellheads camp but not defeat. The confrontation is going on in areas of telecommunication switches and emergency services. Starting in the late 2010s, AT&T is replacing older 4ESS switches with N4E-N1B switches developed by Nokia Bell Labs. Only in 2017, AT&T has been selected by the First Responder Network Authority to build and manage the first broadband network dedicated to America?s police, firefighters, and emergency medical services. The most acute struggle unfolded in the area of defense information systems. According to a recent GAO report (in 2018), the U.S. weapons systems developed between 2012 and 2017 have severe, even ?mission critical? cyber vulnerabilities. The move to the IP world is slow: there is too much risk of losing control over defense forces. Till now the Defense Red Switch Network (DRSN) uses 40 years old ISDN technology. The reason for this is unsolved cyber security issues.