On 26.11.2025 19:22, Mark Tinka wrote:
It was between June - August, this year. The issue was due to an SOA shortage. Nearly every manufacturer was affected by this, on both the ER4 and ER4-Lite.
Some manufacturers have EoL'ed the ER4-Lite builds, and are only focusing on ER4. So if you have access to ER4-Lite supply, you should take it all while you still can :-).
Interesting and good to know, thank you!
The ones we use for our own network and sell via our hardware business are from Smartoptics. They are built similar to FS and FiberMall using 1296/1300/1305/1309nm wavelengths. For the ER4 ones we use and sell from Smartoptics also, they are running 1304/1306/1309/1311nm, which matches what you say Flex are using for ER4-Lite.
Oh that's actually the first I've heard of a manufacturer using different grids for their ER4 lite vs their ER4! Now I get why you were telling me not to combine ER4 lite and ER4, in your experience they use nLWDM and LWDM respectively. My impression was the opposite, that each seller sticks to one grid for both. Examples below: FiberMall list LWDM for both: - https://www.fibermall.com/sale-461143-qsfp-dd-400g-er4-lite-lwdm4-30km.htm - https://www.fibermall.com/sale-458209-qsfp-dd-400g-er4-lwdm4-40km.htm Flexoptix list nLWDM for both: - https://www.flexoptix.net/en/d-164hg-30-e.html - https://www.flexoptix.net/en/d-164hg-40-e.html EdgeOptic list nLWDM for both: - https://edgeoptic.com/products/400g-qsfp-dd/400g-qsfp-dd-41/ - https://edgeoptic.com/products/400g-qsfp-dd/400g-qsfp-dd-42/ FS only have the ER4 lite, Huber+Suhner only have the ER4, GBC Photonics only have the ER4, so they don't provide a useful datapoint here. I found another example for your case too: Fiberworks list LWDM for ER4 Lite and nLWDM for ER4: https://www.fiberworks.no/fiberworks-as/qdd-400g-er4l/qsfp-dd-400gbase-er4l-... https://www.fiberworks.no/fiberworks-as/qdd-400g-er4/qsfp-dd-400gbase-er4-4x... I don't have the insight into who actually manufactures and who sells who's stuff, so these examples might contain duplicate entries for what any one manufacturer does.
I suspect the Flex numbers could be a simple documentation error where someone copied & pasted the ER4 numbers to the ER4-Lite page, but I could be wrong. I would write them and ask.
I was talking to them before starting this thread and they confirmed that the nLWDM spacing is correct. They also let me know that they tested their ER4 lite against their ER4 and they were compatible. So unfortunately it's not so simple. We have a mess in the market, I think. Joel -- Joel Busch, Network Engineer Switch, AS559