AT&T is positioning itself as the pivotal company in an ecosystem of telco-oriented cloud providers. That started a few years ago with its Domain 2.0 supply chain reorganization, introducing new vendors alongside established ones to support its conversion to software-defined networking (SDN), virtualized networks and white box servers and switches. It has built on that internal process by contributing various developments for virtualized networks into open source, hoping to create global de facto standards according to its own vision of the cloud network (these include the Linux Foundation-hosted ONAP and ORAN). And it is assembling an increasingly broad range of strategic partnerships with major IT suppliers, via direct alliances – like those with Microsoft Azure and Amazon AWS – and…