A dynamic MAC (Medium Access Control) protocol demonstrator for ATM PON (Passive Optical Network) was realised and tested. The prototype is based on a SuperPON transport system, which allows implementing downstream grants per ONT (Optical Network Termination) or subdivided per T-Cont class (Transfer Container) and upstream requests by piggybacking or dedicated polling slots. The demonstrator platform was made configurable in order to evaluate dynamic bandwidth allocation schemes for SuperPON and for G.983.dba APON. I.