Patent ID: 7372854

Claim:
A communication node system, which is for Ethernet-PON (Passive Optical Network), the communication node system comprising: an LLID register for storing an LLID (Logical Link Identification) being an allocated identifier; a preamble generator for generating a PON preamble using the LLID; a CRC (Cyclic Redundancy Check) generator for generating a CRC for the preamble; a transmission connector for combining transport data with the CRC-including preamble to generate a transport frame, and forwarding the transport frame to the network; a reception connector for receiving a frame from the network and dividing the received frame into a preamble and received data; a filter for extracting an LLID from the preamble, comparing the extracted LLID with the LLID stored in the register, and selectively filtering the extracted LLID; and a received frame generator for, based on the filtering result from the filter, discarding the received data, or combining the received data with the preamble to generate a received frame.