Methods, systems, and apparatus, for receiving, by an optical line terminal, an upstream communication frame from an optical network terminal, the upstream communication frame including a data packet and a last fragment bit; determining, by the optical line terminal, a fragmentation of the data packet of the upstream communication frame; and processing, by the optical line terminal, the data packet of the upstream communication packet based on the fragmentation of the data packet, including: when the data packet is fragmented, examining a last fragment bit of the upstream communication frame, and storing, in a memory device, the data packet when a state of the last fragment bit indicates that the data packet is not a completion; and when the data packet is not fragmented, transmitting the data packet upstream without storing the data packet in the memory device.