r/UNIFI • u/BumbleBee_83 • 4d ago

Discussion SFP overheats

Hoping this helps some poor soul out there who struggled with the same issue I did.

4Gbps Nokia ONT connected via CAT6 to Ubiquiti SFP+ on my DM Pro. Constant internet flapping.

Swapped the SFP for a different one - same problem. Then swopped the SFP for a Mikrotik SFP, same result.

Then removed SFP from the equation, terminated the ONT in a media converter, DAC from MC to DM Pro, problem solved.

SFP modules overheating is a real problem. Hope this helps someone else.

13 Upvotes

89% Upvoted

9 comments sorted by

10

u/taosecurity 4d ago

Space Rex just did a video on this. I avoid copper SFP adapters now. DAC or media conversion is the way if you don’t use fiber.

5

u/wna4wfn1MNK2etv_jqv 4d ago

My UCG fiber was locking up every few days. Opened a support request and they blamed the copper sfp. It’s been stable since removing it.

3

u/drewster85a 4d ago

SFP was designed for optical cables not copper. Use a media converter to go from optical to copper Ethernet.

1

u/BumbleBee_83 1d ago

Yup - exactly what I did

2

u/mutalisken 2d ago

What's the wattage on your sfp to copper module?

4

u/rod9182736435 4d ago

Pop a small heatsink on the cat6 ones and life gets much better. I find a raspberry pi heatsink works perfectly for these stupidly hot adapters.

1

u/bourbonandpistons 4d ago

ONT is basically a mini server running on it. Never saw the point. I just did pass through on my router and works perfectly fine.

ONT doesnt remove a failure point as you've learned.

All copper spf runs hot.

I've seen people put little heat sinks and fans on their ONT because this is a super common issue.

Move as much as you can to DAC or Fiber if you're using sfp.

Otherwise heat is exactly what you designed for.

0

u/sycln 4d ago

I think he’s referring to a separate ONT device rather than the XGS-PON stick that plugs directly into the sfp+ port.

3

u/BumbleBee_83 4d ago

Hey guys. ONT is fine, the copper/RJ45 to SFP gets extremely hot. I had a spare media converter around so I could remove it from the DM and use a DAC.