This white paper discusses strategies for telcos and service providers to build successful cloud computing services. As traditional revenue streams decline, cloud services provide new opportunities. However, choosing the right cloud infrastructure is important. Proprietary solutions can lock providers in and be costly. Open-source cloud technologies offer lower costs, flexibility, and scalability. While open-source provides benefits, deployment can be complex requiring integration and testing of disparate components. The white paper examines how to successfully build an open-source cloud.