A main disadvantage of both real testbeds and virtualized environments is the high maintenance effort. Especially, if there is a failure during an ongoing performance evaluation, the distribution of a new, corrected implementation is still labor-intensive. To minimize this maintenance cost a central configuration approach is used. As shown in the Figure, a central server, the so-called meshserver, is integrated into the testbed. It offers source- and drain functionalities. The most important service of the source functionality is the provision of an operating system (OS) to all nodes via the network. Therefore, the basic setup is the same in each node of the hybrid testbed. The nodes may even share the same kernel including modules and drivers. Another important service provided by the meshserver is the Internet access, which is required for the mesh gateways. The drain functionality incorporates kernel, system message and SNMP message logging, gathering measurements results of the real and emulated mesh networks, etc. The central logging enables a quick detection of any problem in the testbed.

Besides reducing the maintenance cost, a central configuration and log server offers eased scenario creation and improved controllability. Since the configuration files are stored on a single central server, any WMN architecture or WMN application scenario can easily be realized. For example, it is possible to define which mesh routers should act as a gateways. Furthermore, the routing functionality for the clients can be enabled or disabled. Thereby, a routing mesh client can simply be reconfigured to a non-routing mesh client. Thus, the performance of different mesh architectures can be evaluated and measured.

To interconnect the virtualized environment and the real testbed all mesh routers and virtual machines are connected by a common wired network, the virtual backbone network. The term "virtual" emphases the fact that this network is solely used for booting and configuring the attached nodes as well as for the audit trail processing. That means, the clients in the real testbed cannot use it for their data traffic. Thus, their data is forwarded in a multi-hop fashion via the wireless network interfaces.