Telefonica, one of the world's largest telecommunications providers, is making sweeping changes in how it delivers IT services to the business. It is using a hybrid private-public cloud strategy based on Microsoft software to reduce IT costs by 15 percent, ramp up business agility, and increase data center flexibility and reliability. Its private cloud, based on Windows Server 2012 with the Hyper-V technology, is the cornerstone of a new Tier 4 Madrid data center. There, it will consolidate 18,000 physical servers across Europe to just 6,000 physical servers. With a hybrid-cloud strategy, Telefonica can deliver IT services to the business in days instead of months and make them far more reliable. It reduce IT costs by 15 percent, improve availability and flexibility and increase business agility.