Online game's traffic becomes one of the important traffic over the Internet. In last decade, popularity of the Massively Multiplayer Online Game (MMOG) rapidly increased. Most of MMOG are constructed based on client-server architecture. MMOG needs a network with very low-latency point-to-point in upstream direction and low-latency broadcasted from server to client in downstream direction. In the broad-band access networks, passive optical network (PON) is one of the best solutions to meet the higher bandwidth demands with low-latency. Among PON system Ethernet Passive Optical Network (EPON) due to low cost, simplicity, and provide high bandwidth seems one of the best architecture for the MMOG. In this paper, we introduce a new Optical Network Unit (ONU) architecture and new Dynamic Bandwidth Allocation (DBA) for handling online game's traffic. The proposed ONU is able to classify MMOG game and pass it to new queue instead to send the MMOG traffic to the Best Effort (BE) queue. The DBA can delay MMOG queue for some cycle without effect to the delays. Simulation results depict that our propose architecture can improve the overall QoS in terms of mean packet delay and packet loss.