In this paper, two approaches for Dynamic Bandwidth Allocation in GPON networks are proposed, and validated through simulations in the OPNET modeler. One approach address a Status Reporting scheme, where the bandwidth allocation originates from the client request. The second use a centralized Non Status Reporting scheme. Furthermore, parameters to cope with variances in the traffic pattern is quantified. The results on performance, scalability and efficiency show that Status Reporting is utilizing the bandwidth more efficient while the Non Status Reporting provides better QoS for real time services.