About two months ago, we started to prepare for our new project. Then I contacted my AM to get some technical supports by providing our network diagram with detailed info. For our case, the distance between Site A and Site B is 15 km & Site B and Site C is 8 km. The tech support team offered us two alternative solutions based on our requirements (real-time monitoring). After discussing, we drafted a shopping list. They double-checked the list and advised that we should replace CWDM 40km modules by 80km ones. And they helped us to change the module types covering CWDM-SFP10G-1470, CWDM-SFP10G-1490, etc. It's worth mentioning that they even noted the color of the devices for aesthetics. Combined with professional and considerate, quite impressed.