Parallel Physical Interface (PPI) lies between the Physical Media Attachment( PMA) and Physical Medium Dependent( PMD) sublayers and differs only in the number of lanes. Parallel Physical Interface is self- clocking, has serial links, and uses 64B66B encoding. Each lane has an effective data rate of 10 Gbit/s, which results in a baud rate of 10.3125 GBaud due to the 64B66B encoding.
For 40-Gigabit Ethernet, four transmit and receive lanes are used, each transmitting 10 Gbps. With 100 Gigabit Ethernet, ten transmit and ten receive lanes are used. Each in turn with a transmission rate of 10 Gbit/s.