Ethernet in the first mile (EFM) refers to using one of the Ethernet family of computer network technologies between a telecommunications company and a customer's premises. From the customer's point of view, it is their first mile, although from the access network's point of view it is known as the last mile.
A working group of the Institute of Electrical and Electronics Engineers (IEEE) produced the standards known as IEEE 802.3ah-2004, which were later included in the overall standard IEEE 802.3-2008. EFM is often used in active optical network deployments.[1]
Although it is often used for businesses, it can also be known as Ethernet to the home (ETTH). One family of standards known as Ethernet passive optical network (EPON) uses a passive optical network.