The IEEE 802.3 sublayers within OSI Layers 1 and 2 are mostly preserved, with a few additions to accommodate 40 km fiber links and interoperability with SONET/SDH technologies.

• 在OSI第1和2层内的IEEE802.；3子层大部分都被保留，只有些许的增加以顺应40km光纤链结以及与SONET/SDH技术交互运作。