Thunderbolt 3 to Fiber Media Converter

[coco3431]

Hello All!

Lately I've been wishing I could run Thunderbolt over fiber in my apartment but the only option I've found is from Corning, which while not bad isn't exactly what I'm looking for. I have an QSFP+ 40Gbps fiber cable with transceivers sitting around collecting dust and started looking into if anyone was making media converters, similar to ones that exist for HDMI to SFP+ and back. Unable to find any I started to research how I could build such a device, but have some concerns. I'd appreciate some pointers/advice just to make sure I'm on the right track. It seems like I can just send differential signals into a transceiver and as long as they're both powered it will get spit out on the other transceiver. This sounds almost too easy and I can't help but think I'll need some kind of redriver chip after exiting the transceiver. But maybe that would mess up latency/timing of the signal? I'm not too worried about the actual high-speed routing, I've had success with PCIe3.0 and USB3.0, more just trying to figure out what is all required for this type of conversion to be successful. I'm also aware that there's extra non-differential pair communications (SBU1/2, USB2, and CC Pins) but I'm less worried about those as they're much slower in comparison and I could send them over a separate bus/cable.

TLDR Question: Can I just connect Thunderbolt 3 differential pairs to an QSFP+ transceiver or is there more complication to do so?

Thanks!

[Hydron]

All I can say is that don't just assume that USB2 will be easy due to being "low speed" - I wouldn't be surprised if that is far harder to deal with than the Thunderbolt stuff.

[Someone]

TLDR Question: Can I just connect Thunderbolt 3 differential pairs to an QSFP+ transceiver or is there more complication to do so?

Possibly? The two transports you want to jam together do use the same symbol encoding, so it might just work.

Cost of working all that through vs buying the ready made cable? I wouldn't be experimenting.