Three different test areas were tested in parallel during the hot-staging. Small groups were used to check interoperability and scalability. Successful groups in this stage were then connected to form larger groups to build the multi-vendor network. The integration of the groups went forward smoothly and at the end of the hot-staging, all participants formed a piece of the demonstration network.

Initial interoperability tests were done in groups of three devices connected to each other. Later on, all devices of each scenario were connected to separate multi-vendor networks for VPNs and the MPLS-DiffServ backbone. Finally, the VPN networks were attached to the edges of the MPLS-DiffServ network and thus integrated into one large common infrastructure. Further interop testing and traffic load generation was done at this stage to verify that VPN traffic benefited from traffic differentiation.