This April 2012 NSA presentation uses an AT&T specific term – Common Backbone or CBB – to refer to the Internet backbone of the corporate partner it codenames FAIRVIEW: see the New York Times article AT&T Helped U.S. Spy on Internet on a Vast Scale, 15 August 2015.
This presentation gives an overview of the NSA’s programmes targeting the fibre optic cables that carry much of the world’s internet traffic. One slide gives a breakdown of which data sources form the basis of Presidential daily briefings. Another shows that the access point used to collect Yahoo and Google cloud data (MUSCULAR) is operated by GCHQ on UK territory. Slides detailing RAMPART cable accesses were published by the Intercept on 18 June 2014: see the Washington Post article How we know the NSA had access to internal Google and Yahoo cloud data, 4 November 2013.