Sprint’s strategy for virtualization and software-defined networking (SDN) has been less publicly discussed than AT&T’s but has some points in common, including a major inhouse development of a platform which has now been placed in open source, and the use of SDN to shake up its traditional supply chain. The operator has revealed more details of its NFV (Network Functions Virtualization) approach, which – as for many telcos – is starting with a virtualized evolved packet core (EPC). It has also named two of its suppliers, Metaswitch and Mavenir. The vEPC work is based on Sprint’s own reference design, called C3PO (Clean CUPS Core for Packet Optimization), which was unveiled in May and open sourced (hosted by the Linux Foundation)…