Open Source and FPGA Maker Board for Networking

I've had some fun learning how to implement various bits and pieces of networking on FPGAs as a hobby for a while, and while boards like this that focus on gigabit network are fine, the fact is that there are a lot of FPGA boards with gigabit and 100Mbps interfaces. What there are not enough of are low cost boards that can do 2.5Gbps, 5Gbps and 10Gbps. Lattice has some very affordable FPGAs with 5Gbps SERDES, and their newer 10Gbps capable chips remain extremely affordable.

One of the things I would absolutely love to have are a couple of FPGAs boards in SFP and QSFP form factors. Why might you ask? Because it would be seriously useful to have a PPPoE / L2TP data plane to plug into the port of a 100Gbps capable switch for use in the network edge. Modern ethernet switches have plenty of Layer 3 networking capabilities, but most switch vendors fail to expose any functionality for these protocols even though the underlying ASICs often enough have the capability to handle them. Sure, you'll never see these protocols in a cloud data center, but plenty of incumbent telecoms make use of them in their FTTP networks due to the legacy of xDSL deployments and the need to support wholesale access to those networks. Sadly, developing such a board is beyond my hobbyist electronics capabilities, but I'd have no problem bashing a bunch of Verilog / VHDL into shape to make it work in fairly short order... I just hope it uses an FPGA like the Polarfire for which the SERDES are about 100x easier to use than the gawd awful Xilinx 7 series (KC705, I'm glaring at you for eating weeks of my hobbyist life to that bring up).