EFM also addresses other issues, required for mass deployment of Ethernet services, such as operations, administration, and management (OA&M)[REF] and compatibility with existing technologies (such as plain old telephone service spectral compatibility for copper twisted pair).
100BASE-LX10 defined in clause 58, providing point-to-point 100 Mbit/s Ethernet links over a pair of single-mode fibers up to at least 10 km.