Ethernet First Mile (EFM) connections are sold in two flavours - a broadband version and a non-broadband version.
EFM broadband has a contention ratio of 5:1. That means your connection's backhaul bandwidth is shared with up to four other subscribers. At peak times, your throughput could drop to 20% of your connection speed. So, a 20Mbps EFM broadband connection might only allow you to send or receive data at 4Mbps.