DES-TBMS (Testbed Management System)

Two different kinds of software are needed to operate the DES testbed. The operating system of the mesh routers provides hardware abstraction and allows the execution of programs for experiments. Additionally, a global management framework enables monitoring and configuring the DES-Nodes and scheduling experiments. This function is provided by the testbed server.

In order to minimize the number of constraints of experiments, a customizable and open operating system is needed for the mesh routers. Linux fits our needs as it is already used in our day-to-day research. We make use of the most recent kernel and driver versions and try to keep up with the developments of the community.

The testbed server is the central entity in the DES testbed and provides various services for the DES-Nodes. It hosts the file systems which are mounted by the mesh routers via network file system (NFS), using their Ethernet connection. Additionally, the testbed server runs a PostgreSQL database, which is used to store logging data and measurement results obtained from experiments. Next to these infrastructural services, the server hosts the management software that enables convenient handling of the whole DES testbed and simplifies the execution of scheduled experiments. It consists of a web based application, implemented in Java, that comprises the following integrated components.

DES-Exp

This software provides an experiment manager which is responsible for the scheduling and execution of experiments. Experiments can be specified using DES-Cript, as described in Chapter 5 of the corresponding technical report, and scheduled to be executed. DES-Exp features a sophisticated user management module to ensure simultaneous multi-user access to the testbed.

DES-Cript

Experiments are describe with an XML-based domain specific language (DSL). This approach allows to conveniently map the outlined logical structure of an experiment to hierarchical sections. The easy-to-read property of XML satisfies the goal to make experiments comprehensible and easy to understand for other users. A particular experiment description can be run multiple times, thus making experiment repetitions an easy task.

DES-Mon

This software component provides a tool to monitor the network state during experiment runs. It is also used as a configuration tool based on SNMP and allows the user to pre- and post-configure the DES-Nodes.

DES-Eval

The evaluation tool consists of a suite of Python scripts to support automatic evaluation of commonly used tools in network experiments such as ping and iperf. A user can specify for experiment actions if a particular script processes the generated output. The testbed server runs the script and inserts the extracted data into a database, where they can be retrieved for further evaluation. In a second step, additional scripts can process the results to generate basic types of graphs.

We are currently refining the software to make it available to the public.