Ethernet Passive Optical Networks (EPON) are high speed, all fiber networks with bi-directional speeds of 1 Gbps per port. Each ONUs (Optical network units) signals are multiplexed in the time domain. ONUs see their own data through the address labels embedded in the signal. The ONU is the DOCSIS equivalent of a cable modem. The ONU connects optically to an Optical Line Terminator (OLT). The OLT is the DOCSIS equivalent of a CMTS, only much faster. An EPON network does not offer the same quality of service as DOCSIS networks, but what it is lacking in features it makes up for in speed. EPON does offer virtual LAN (VLAN) support which is being used for effective QoS. In addition new features are being added to the EPON chipsets such as integration with DOCSIS back office provisioning called DPoE. The bottom line is that cable operators see EPON is a great addition to the future expansion of high speed data in the cable communications world.
Data Over Cable Service Interface Specification (DOCSIS) Provisioning of Ethernet Passive Optical Network, or DPoE, is a set of Cable Television Laboratory specifications that implement the DOCSIS service layer interface on existing Ethernet PON (EPON, GEPON or 10G-EPON) Media Access Control (MAC) and Physical layer (PHY) standards. For cable operators looking to implement EPON, DPoE is a fantastic standard. An subscriber can have an ONU installed, purchase a service plan for 30 Megs down and 10 Megs up. The cable operators simply provides the MAC address of the ONU with the DOCSIS configuration file of a 30 x 10 service tier (this is done in the provisiong system). DPoE takes care of the rest by translating the DOCSIS service flows into relevant VLANs for the EPON network to that specific subscriber.