Network slicing represents a new paradigm to operate mobile networks. With network slicing, the underlying infrastructure is "sliced" into logically separate networks which can be customized to the specific needs of their tenant. Hand-on experiments on this technology are essential to understand its benefits and limits, and to validate the design and deployment choices. While some network slicing prototypes have been built for the radio access networks (RANs), leveraging on the wide availability of radio hardware and open source software, there is currently no open source suite for end-to-end network slicing available to the research community. In this paper we fill this gap by developing an end-to-end network slicing protocol stack, POSENS...