10G/25G Fiber Backhaul: Planning GTX/GTH Line Rate and UDP Offload
When multiple high-speed ADCs, radar beams or video streams come together, copper cables top out after a few meters and PCIe cannot leave the chassis. The right backhaul is to drive SFP+/QSFP directly from the FPGA's GTX/GTH transceivers, offload the MAC and IP/UDP stack on-chip, and send only the payload over fiber at line rate. This article works out the 10G/25G line rate, UDP payload, link budget and the FPGA's internal division of labor.