On 28/11/2025 11:34, Joel Busch wrote:
Yes we're seeing the same. And when I ask a customer if they would like their uplinks to be 100G-LR4 or 100G-LR they ask me what 100G-LR is :-)
Wait when SFP-DD starts to become a thing :-). We have started shipping these to some customers in Africa. Great for density when you can slot 44x 100G ports into a 1U line card. Single-lambda 100G is definitely the way to go. LR4 just eats up too much space and pays the data centres a lot more in x-connects than I'd like.
And with ER4-lite all bets are off. It's anyone's guess which shop will sell which spacing, just make sure your inventory stays consistent for your own sanity.
I think the commercial gap between 400G-ER4/ER4-Lite is closing quickly enough that for most people green-fielding short-haul 400G above 10km, 400G-ZR+ coherent will look a lot more attractive. Especially because you can bolt on an amplifier and extend that 400G beyond 60km, or reduce the modulation and increase reach for slightly lower speeds (100G, 200G or 300G). 400G-ER4/ER4-Lite being O-band does not lend itself to being amplified. My advice to anyone thinking of 400G-ER4/ER4-Lite would be to consider 400G-ZR+ instead. 800G-ZR+ will help to lower 400G-ZR+ pricing even further, by the end of 2026. My prediction is that 400G-ER4/ER4-Lite fades into the darkness like 100G-CWDM4 did. Mark.