The IEEE working group 802.3cd has specified several 100GbE interfaces for fiber, twinaxial cable and copper cable for 100 Gigabit Ethernet
. With 100GBase-CR2 there is a 100GbE interface that works with twinaxial cable. Transmission is on two lanes with four twinaxial cables over short distances. As a module, 100GBase-CR2 uses the CFP module. 100GBase-CR2 works with pulse amplitude modulation and can bridge distances of 3 m.