The first discussions about bring virtualization and SDN (software-defined networking) to carrier networks revolved around the cost savings. Implementing key network functions as software applications (often open source) on commodity hardware, rather than investing in expensive, proprietary appliances, would be the way to accommodate exploding levels of data usage without breaking the bank. This was the strategy of desperation. According to John Donovan, AT&T’s senior EVP for technology and operations, the carrier’s global network experienced 100,000% growth in wireless traffic between 2007 and 2014, and such curves could not be profitably supported by adding new hardware. Instead, AT&T aims to virtualise 75% of its network, stripping down each component to its core and re-architecting it for the cloud, as he…