After this course students will have an in-depth understanding of cross-organisational and cloud-based systems and an overview over the state of the art. They will be able to name and describe the architectural principles from Infrastructure over Platform up to Software as a Service concepts. Students will have an understanding of the different cloud software stacks and solutions, and will be able to assess their advantages and limitations. Additionally, they will understand the challenges and solution approaches to deliver Cloud-based services not only from a consumer's, but also from a data centre operator's perspective. They will also learn how Service Level Agreements help in meeting business requirements. The students will be able to differentiate between cloud solutions and local systems and assess them from an economic viewpoint. At the end of the course, the students will have an understanding of the challenges addressed by current research projects.

In the first part of this course, the basics and specific challenges of cross-organisational distributed systems will be discussed. Starting from approaches such as Metacomputing, Grid Computing and virtualisation technologies, the concepts behind Clouds will be introduced. The different layers of Cloud provisioning (XaaS) will be explained in the context of current Cloud-based solutions. It will be explained how the concept of Service Level Agreements affect Cloud service hosting and delivery, in particular in terms of performance and cost. The impact on networks and the relationship to Network Function Virtualization and Software Defined Networking will be discussed. The course will conclude with selected themes from "Future Clouds" and current research and development efforts in academia and industry. Lectures will be amended with guest speakers from collaborating institutions from academia and industry, where appropriate.