Ethernet Passive Optical Networks (GEPON or EPON) is the leading technology being used in FTTx (FTTH) deployments. PON is different than other optical network topologies in that it is a Point to Multi-Point (P2MP) topology. From the Central Office’s (CO) Optical Line Terminal (OLT, with SFP GEPON transceiver/module) a single strand of fiber goes out to a passive optical splitter where its signal is multiplied to 32(64) different lines. The Transmit and Receive signals operate on different wavelengths allowing bi-directional operation over a single fiber. Anything transmitted from the OLT is transmitted to all 32 lines. It is up to the customer’s system (Optical Network Unit - ONU) to determine what packets are for that customer. All other packets are discarded. The PON current standards have defined downstream data rates up to 1.25Gbps.

# IEEE 802.3ah. EPON or GEPON (Ethernet PON) is an IEEE/EFM standard for using Ethernet for packet data.