sfps from fs dot com

Anyone have experience with fs.com's lasers? Are they reliable?


I've had no complaints about reliability. In terms of transmit power and receiver performance, they seem to have a bit more variability than some of the bigger brands' offerings, but they seem to always be within spec.

They're cheap enough to keep several spares around and still come out ahead of buying name-brand let alone OEM vendor-branded optics, too.


We have maybe 1:50 DOA, but they’re so cheap, we just throw them out because it’s not worth the RMA.

That said, I can’t remember the last time we’ve had any of these fail in the field, or have had any issues with variablity in TX/RX power. We have tens of thousands of these in the field, from 100Mb Bidi to 100G-LR and everything in between, including *WDM up to 80KM.

It boils down to a business case.

In my travels we see a high failure rate -- higher than I'd like to see --, but $boss likes the price, and, as Jason pointed out below, for the price, it can be a "successful" business model.

In a nutshell:

For someone on a budget, they're great; buy spares.

For someone who doesn't want to deal with outages, call-volume, hands tickets, truck-rolls, and has money to burn, there are better alternatives.

Indeed. My tune would be very different if we had 1:50 fail in the field.

I’ve got a whole bunch running with no issues… Mostly MM/850nm though, so maybe a bit different than their SM stuff. Also have a handful (literally) of the SM ones, and haven’t had any issues (yet).

Only “problem” I’ve had is a copper SFP from them which may have burned out and fried a switchport… oops.

Yes. I never have seen a failure in the last few years.

We have used Cisco compatible 1G / 10G DAC, SR, LR, and DWDM.

Buy spares if you are concerned, they are priced so you can.

We do like having spares in a rack drawer.

Thank you,

Kevin McCormick

Biggest issue I've seen is it may work on some Cisco models and not others. I got their flashing box to just reflash the firmware and that has fixed even "dead" optics.

Had some issues in the past with Juniper-coded LR4 with sporadic disconnections. Apart from those I don’t have any complaints beyond the odd DOA.


We buy them extensively and have had zero data problems with more than 300 parts in the field. Some switch/router manufacturers’ firmware poutily refuses to let you read snmp stats from any “unauthorized” SFPs modules, and some oem salespeople lyingly claim that using them voids your warranty, but this is just an attempt to keep customers captive to insanely overpriced OEM parts.

FS.com’s bi-di modules are particularly ingenious, letting you add bidirectional fiber to devices the oem manufacture doesn’t even sell optics for in an attempt to create artificial product segmentation.


And if you buy them coded to said switch/router vendor (or code them yourself with the "fs box" which is reasonably priced), said switch/routers usually start cooperating for you.

I have had some fail and SFP+ & QSFP28s that my Juniper MC480s refuse to recognize even though I ordered 'branded Juniper' optics.

99% of my stuff is from FlexOptix (https://www.flexoptix.net/). They are a bit more expensive but I've had 100% reliability and they have worked in all systems I've put them in.

We have had some failures with 10G BiDi optics coded for Juniper. We buy a ton of other stuff from FS but for optics we have moved over to Approved Optics for everything but active ethernet residential subscribers.

Nicholas Warren wrote :
Anyone have experience with fs.com's lasers? Are they reliable?

I have a few hundreds of them, started buying from them about 3 years ago, not a single issue so far.
I'm going to buy their box soon, so I could recode a Cisco optic into an HP one, easier on spares management.


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Another vote for Approved here, awesome group of people and very thorough in their testing and fault analysis. We buy from them for Juniper, Ciena, Mellanox, Intel and a bunch of other random stuff.

I’ve had mixed results with FS. Some stuff works fine, others we have high failure rates on longer term after 18 months give or take a little bit. The failed units typically come from interfaces that run at very high utilization levels 24x7 but have never done any more correlation than that.


Back last year, I experienced less than expected reliability with QFX and their QSFPs.

We prefer to use optic.ca since they’re a few minutes from our DC’s and will respond within the day, with platform and firmware changes, which we can test in lab before shipping to our remotes.

The price difference is made reducing downtime in our case.