Classification ambiguity in Cloud Computing has a catastrophic impact on cloud providers, their services and tenants. It limits the application of various network services to traffic either inside or outside a cloud. This is because IP addresses, VLANs and other transport-level technologies lack the functionality to cope with the highly dynamic, scalable and virtualized environment of cloud-enabled data centers. In this paper, we present the prototype design and discuss its features. We also evaluate the UCC proposal in a cloud-enabled data center environment. Our examination of the compatibility, performance and usability of UCC shows that this scheme is not only feasible, easy to implement, but also has significant advantages over other classification techniques. For example, it enables highly desirable functionality such as traffic volume-based data center billing. Imminent follow-up efforts include scalability testing of UCC on the open Internet. We are confident the UCC scheme can provide a long-term, practical and flexible solution for cloud classification with significant benefits.