10 Gigabit Media Independent Interface

XGMII : (Copy from Wikipedia)

two 32-bits datapaths (Rx & Tx)
two 4-bits control flows (Rxc & Txc)
operating at 156.25 MHz DDR (312.5 MT/s).

XAUI:

XAUI has the following characteristics:

• Simple signal mapping to the XGMII
• Independent transmit and receive data paths
• Four lanes conveying the XGMII 32-bit data and control
• Differential signaling with low voltage swing (1600 mV(p-p))
• Self-timed interface allows jitter control to the PCS
• Shared technology with other 10 Gbit/s interfaces
• Shared functionality with other 10 Gbit/s Ethernet blocks
• Utilization of 8b/10b encoding