Never failed me, always delivered on time or ahead of the estimated delivery. And the one supplier offered the right 100GBASE-CWDM4 QSFP28 1310nm 2km optical transceiver for my Netberg Aurora 750 switches On a Tofino chipset.

The QSFP28 CWDM4 modules arrived with comprehensive protection and work flawlessly in our Huawei switches. Nice transceivers!

Our testing equipment required a 100Gbps rate, and the integrated network equipment required 25Gbps. So we planned to buy 2km 100G module. The module should support 100G to 4x 25G transmission. We thought FS #65786 may suit our needs. But it uses LC interface, so we talked with FS technician and asked whether we could use this product to do 100G to 4x 25G transmission. The guy said, we could use a DEMUX to achieve that conversion. And he also offered the specification of the DEMUX, it should be a 4 channel CWDM MUX DEMUX with 1270-1330nm wavelength. So we still needed 25G CWDM modules with the corresponding wavelengths.
We bought all the products. Installed them as the technician suggested, all was going well.

Needed to upgrade to 100G over Arista 7280SR2K switch. We chose this product. Installed on the switch, it did exactly what it needed to do. Haven't seen any errors.

I need to upgrade a computer room to 100G and want some 100G transceivers on Arista 7280 and 7050 switches. After telling the details to my AM, he suggested using this CWDM4 module. Working well with no problems.

We have gotten a couple dozen patch cables of various kinds, 40 SFP+ modules of various compatibility, a couple of QSFP+ (40GBASE-SR4) modules & MTP-LC breakouts. Their modules are of impeccable quality. Everything has worked flawlessly. QSFP-100G-CWDM4 100GBASE-IR4 Lite QSFP28 Transceiver Module is said to be capable to run on Arista 7280 switch. We have not put in to use yet. One thing is that it not only supports the connection with 100G CWDM4 transceivers, but also, being tested by the tech person as we wished, works out to connect four 25G CWDM SFP28 transceivers (1270nm, 1290nm, 1310nm and 1330nm). Now we have a program to build two 100G links, two 40G links and several 10G and 25G links between two data centers at a distance of 5km. Product list has been approved. One 100G is built with the DWDM system and 100G ER4 transceivers in path 1; another is set alone with 100G LR4 transceivers in path 2. It is worth mentioning that they offer to have a try with 100G LR4 all at first for the budget’s sake. The leaders verify the feasibility and want to try it as the 100G ER4 and 100G LR4 transceivers have a big price difference. We all think highly of FS expertise and will look for FS next time we have network requirements. Lead time and shipping speed is extremely fast, and their customer service is second to none.

Get a pair of this 100G QSFP28 optics to create a 100G link between a Mellanox SN2700 switch and a Dell z9100-on switch within 2 km. These work fine.

I wanted to use the 100G transceiver to realize the breakout mode 100G to 4*25G. The QSFP28 PSM4 on the website says the max cable distance is 500M which is shorter than what we need. The LC connector seems to be impossible for the breakout mode. Also lost in the selection of the 25G transceivers and the cables. The FS folks said the demultiplexer can be added to facilitate the 4*25G breakout transmission by 2km 100G transceiver. They designed the program and offered the product list according to what devices I have.

100G transceiver:
QSFP-100G-CWDM4-S QSFP28 1310nm 2km Transceiver Module
25G transceivers:
1. CWDM-SFP25G-1270-10 25G 1270nm CWDM SFP28 10km Transceiver Module
2. CWDM-SFP25G-1290-10 25G 1290nm CWDM SFP28 10km Transceiver Module
3. CWDM-SFP25G-1310-10 25G 1310nm CWDM SFP28 10km Transceiver Module
4. CWDM-SFP25G-1330-10 25G 1330nm CWDM SFP28 10km Transceiver Module
Demux:
4 Channels 1270-1330nm, LC/UPC, Dual Fiber, Low Insertion Loss CWDM Mux Demux, FMU Plug-in Module
Cables: LC Duplex OS2 Fiber Optic Patch Cables

Here are what I get from FS. All is working fine for me since installed. Great product for my needs.

The QSFP-100G-SM-SR transceiver modules purchased here have been working flawlessly on Cisco N9K-C93180LC-EX and Cisco N9K-C93180YC-EX switches for almost half a year. Now we have Arista 7160 100G switches to be connected from one side of our building to the other, and the QSFP-100G-CWDM4 100GBASE-IR4 seems to be the best choice. The cable run is over 200M but under 2km, singlemode lc/lc. Not sure whether we should be breaking out CWDM/DWDM ourselves. Good news is the QSFP-100G-CWDM4 can connect the 100G CWDM4 transceiver modules directly without the MUX/DEMUX. I endorse FS for their impeccable transceivers that work errorless on my Arista and Cisco switches. We also heard praises of FS switches’ unparalleled cost performance, and found it quite a surprise that what we have spent on a 10G switch of other supplier can bring home an FS 100G switch. Worth a try if they really work great like what others have described.

I ordered four 100GBASE-CWDM4 QSFP28 transceiver modules. All worked great over the past week on Dell EMC S4128T-ON switch.