I'm facing a project that includes 10Gb Ethernet (?) interface on a custom board to a remote PC NIC. I'm really new to this argument so i put some basic questions and hope someone of you could help me understanding the matter. 1)Could 10Gb link be either on fiber or on copper cable? 2)Assuming to instatiate 10G MAC and XAUI in my CIV device, I guess 4 CIV Transceivers(3.125Gbps) are used that, if I'm rigth, would need 4 SFPs attached to connect the fiber. Is that correct? 3)if my guess in 2 is correct: does it means that to get a 10Gb link with only one SFP a device with 10gbs transceivers is needed? 4)Would it be meaningfull to instantiate only 10G MAC on FPGA then connect to a 10G external PHY which in turns connect to the SFP? In this case, would it mean that interface between CIV MAC and external PHY would be done in XGMII that carries something like 150 digital signals? Any comments is really appreciated. Thanks a lot in advance to everybody.