Clearwater is designed from the ground up to run in the cloud providing voice, video and messaging services to millions of users, using from the software design principles of the Web – such as horizontal scalability, NoSQL and, statelessness – and building on those to provide the robustness and standards compliance expected of an IMS core at the centre of a telco-grade communications network. Its software-only approach and simple configuration makes it extremely well suited for deployment in a Network Functions Virtualization (NFV) environment. It has already been used as an exemplar VNF (virtual network function) by CloudNFV, Cloudify, OPNFV and Canonical, and deployed live as the backbone of the Indoona VoIP service in Italy, and other major service providers.

This talk covers the key aspects of Clearwater – what an IMS core is and how it fits into a telecommunications network, how Clearwater differs from traditional telecoms appliances, what architectural principles have been followed in building it, how open source has contributed. It will also describe the work we’ve done to make Clearwater easy to integrate with NFV orchestrators – from the DevOps installation approach, to an etcd-based automatic clustering manager.