There’s only one L2 Ethernet, but there are many many L1 Ethernets. 1000BASE‑T and 10GBASE-LR are by far the most popular L1 standards and that’s probably why y

There’s only one L2 Ethernet, but there are many many L1 Ethernets. 1000BASE‑T and 10GBASE-LR are by far the most popular L1 standards and that’s probably why you don’t hear about the other 1000 standards.