Design and Implementation of the NORNET CORE Research Testbed for Multi-homed Systems

The Internet has made it possible to communicate and to use services over large geographical distances. While it has originally been built for less critical services like e-mail and file transfer, it is nowadays also increasingly often used for availability-critical services like e.g. e-commerce or healthcare. Clearly, the reach ability of such services must be ensured by so-called multi-homing of endpoints. That is, endpoints are simultaneously connected to multiple Internet Service Providers (ISP) to provide redundancy. If one ISP has problems, it is intended that the connection to another one still works. However, such assumptions have never been verified in real, large-scale setups. The intention of the Nor Net project is to build up a realistic Internet test bed for multi-homing. In this paper, we describe the design of Nor Net with focus on the implementation of its fixed-line part: \noun{Nor Net Core}. This paper is intended to give researchers an overview of its mode of operation, its capabilities as well as its interesting feature realisations. The knowledge about these items is very useful to plan own experiments in the Nor Net test bed.