100G coherent ports have been the dominant port rate used in WDM coherent transmission systems for the last seven years. This is now changing rapidly with the availability of 200G and 400G multi-rate technology. 200G port shipments have taken off in 2019, with 3Q19 port shipments up 97% YoY. The move to higher transmission rates is fueled by bandwidth growth. In 3Q18, the ratio of 100G to 200G ports was 2.5 to 1; just three quarters later in 2Q19, it was 1.1 to 1. Clients, please log in to view the full content.