I made a fiberoptic link between two routers. It uses 300m of simplex cable, single mode and bidirectional transceivers. One of the routers is connected to the internet. It worked for a few weeks and then didn’t; now I’m not getting internet at the other router. The media converters don’t show much activity on the tx/rx leds, just a flicker now and then. I power cycled everything, but that didn’t help. Please suggest ways to troubleshoot this (except the obvious one: swap in known good parts). Thanks.
Fiberoptic link not working
- Thread starter sidtupper
- Start date
- Status
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
This is an electrical forum. You question would be better served on a computer forum however there are guys here that may know what to do so I will allow the thread.
zbang
Senior Member
- Location
- Roughly 5346 miles from Earls Court
Is optical link indicated at both ends?
Plug a laptop directly into the router... does that work? If not, it's the router or the ISP, call them.
Plug a laptop directly into the router... does that work? If not, it's the router or the ISP, call them.
Start with basics..
You have a light or OTDR to check the fiber cable?
300 meters is pretty long and mice love fiber optic for some reason.
What media converter are you using? What fiber connector type are you using (e.g. SC), and what color is it (color typically indicates how the end is polished)?
Can you move one router so it is temporarily next to the other one? That way, you could just use a wire cable between them to make sure the router configuration supports that link. If it doesn't work on wire, it won't work over fiber.
Can you move one router so it is temporarily next to the other one? That way, you could just use a wire cable between them to make sure the router configuration supports that link. If it doesn't work on wire, it won't work over fiber.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- Semi-retired engineer
Did you make the cables up yourself? There are non-obvious things that can go wrong when you make up fiber optic cables if you don't know what you're doing. You also need to be able to test them before you try and put them into service. The fact that it worked for a short period of time is a little troubling. It suggests something has changed since you installed it. Possibly one end or the other has flexed and lost light transmission through the fiber optic cable. There are generally diagnostic LEDs and other diagnostic features on routers to help you determine just what is going on but these diagnostic features are not always real obvious to the uninitiated.
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Did you clean the cable ends before connecting?
MM or SM?
MM or SM?
grich
Senior Member
- Location
- MP89.5, Mason City Subdivision
- Occupation
- Broadcast Engineer
Oh yeah...we have an outbuilding under a radar installation with a 20-something-year old multimode cable with six strands of glass made up. The meeces have chewed through the fiber strands twice now in the remote building in the termination tray. i leave the tray swung open now to discourage mice from nesting there. We also sealed up some holes in the building with concrete, which has helped a lot.
We have several runs of single-mode fiber running through the main building in orange smurf-tube. Our biggest issue is accidentally using SFP's that fit mechanically, but don't talk nice to the router firmware.
Agree with basics first...test for light passage. If your media converters are SFP's check for compatibility with your routers.
hbiss
EC, New York NEC: 2017
- Location
- Little Falls, New York NEC: 2017
- Occupation
- EC
You probably shouldn't be using a router at the far end, just a switch.
That said, it sounds like you don't have any experience with this kind of thing if you can't figure out if the first router is working. It sounds like you bought a bunch of stuff off the internet and DIY'd it.
As far as troubleshooting goes, this isn't rocket science. Check at a port on the first router, check at the ethernet port on the far media converter then check at a port on the far router. That will tell you where your problem is. It would be nice if you had a short fiber patch cable so that you could connect both media converters together on the bench to see if there is throughput. That way you could rule out a problem with them. Electronics are not repairable so replace as necessary. I have no idea how you ran the fiber and if the problem appears to be there you are going to have to figure out what happened and how to fix it.
Beyond this we are just wasting our time.
-Hal
- Status