Method of detecting effective frame length for preventing fragment loss in ethernet passive optical network media access control

摘要

A method of detecting an effective frame length for preventing a fragment loss in an EPON(Ethernet Passive Optical Network) MAC(Media Access Control) is provided to manage plural reference values for plural Ethernet frame buffers by using a minimum sized frame length memory of an ONU(Optical Network Unit). A reference value for a size of data to be transmitted is set in a frame buffer. A remaining frame length, which corresponds to a difference between a sum of input Ethernet frame lengths and a smallest reference value of the reference values greater than the sum of the lengths, is obtained. When the length of a new Ethernet frame is smaller than the remaining frame length, a sum of the previous Ethernet frame lengths is detected as an effective frame length. Otherwise, the sum of the previous Ethernet frame lengths and the sum of the new Ethernet frame lengths are detected as the effective frame lengths.