The paper proposes a resources allocation method for EON based on a modified RDM using squatting and kicking strategies in order to prioritise the usage of channels and enhancing the total utilisation. It can also be used as an admission control. The mechanism is described and compared to existing proposals, regarding the flexibility in the allocation per class. The strategy regards the EON constraints and assumes the optical spectrum to be partitioned and reserved to several different classes. These partitions are allocated according to the priority of the demands and the strategy proposed. The performance metrics are explained and analysed via demands and resources allocation examples.