To date, the mainstream Ethernet Passive Optical Network (EPON) bandwidth allocation schemes as well as the new IEEE 802.3ah Ethernet in the First Mile (EFM) Task Force specifications have been centralized, relying on a component in the central office, Optical Line Termination (OLT), to provision upstream traffic. Hence, the OLT is the only device that can arbitrate time-division access to the shared channel. Since the OLT has global knowledge of the state of the entire network, this is a centralized control plane in which the OLT has centralized intelligence. One of the major problems associated with a centralized architecture is the "single-point of failure" problem that is the failure of the OLT software will bring down the whole access network. It is the purpose of this work to propose a distributed solution to this problem, and to devise and experimentally demonstrate the feasibility of implementing a novel Ethernet over Star Coupler-based PON architecture that uses a fully distributed time division multiple access arbitration schemes. Specifically, we assess the viability of implementing a distributed control plane architecture that facilitates internetworking among connected users.
In addition to the added flexibility and reliability associated with distributed control plane architecture, as well as emulating shared LAN capability among different users, the distributed networking architecture and the associated bandwidth allocation algorithms have characteristics that make them far better suited for provisioning Quality of Service (QoS) schemes necessary for multimedia services over a single line.