Fibre connectivity issue

I'm doing some work experience at a school and they're having some issues with fibre connectivity. I know nothing about fibre, so I do apologize if I say something stupid.

Two rooms, two fibre patch panels, two fibre ethernet converters. They have a bunch of fibre cables, each end of the cable has two fibre connections (so, I guess that's what multimode fibre is, I guess one is rx and the other tx). My question is, how are the fibre cables supposed to be plugged into the fibre patch panels and into the converters? Here is how I think it should be:

Room 1

Fibre patch panel port 1 - blue end
Fibre patch panel 2 - white end
Fibre converter Rx blue end, Tx white end

Room 1

Fibre patch panel port 1 - blue end
Fibre patch panel 2 - white end
Fibre converter Rx white end, Tx blue end

No idea if the colour of the fibre connections mean anything (they have blue and white ones, grey ones, etc). All I'm doing is keeping the colours the same, and then changing them around on one side that's connected to the converter. So, when this is all plugged in as I have described the converter lights should light up on the fibre side, but they do not. I have nothing plugged into the converters ethernet port, I only want to test the fibre connectivity. Have tried beaming a laser down the fibre patch panel, we do see light. Beamed laser down the fibre cable itself, and again we see light.

Any ideas as to what the problem could be? My knowledge is limited to pretty much what I have posted here, and I don't think the people who run the network are very clued up on what's going on either.

Thank you

Find more posts tagged with

Free for TechExams community: Cybersecurity salary guide

Compare cert salaries and plan your next career move

Button

Comments

NinjaBoy

You don't say exactly what the issues are, so generally speaking it could be a few things:

1. Faulty fibre convertors... Not sure why you're using them, the school should get proper fibre modules like this one if using HP kit:

2. The fibre end are dirty, Example

Are just a couple of reasons

Eildor

NinjaBoy wrote: »

Could be a few things:

1. Faulty fibre convertors (not sure why you're using them, the school should get proper fibre modules like this one: from HP, if using HP kit)

2. The fibre end are dirty:

To be quite honest I have no idea what they are doing... sounds wrong to have a fibre connection that then goes through a 100mbps converter...

The fibre cables they are using look just like this:

Converter is an Edimax, think it's the ET-912:

terryfera

Some things to check:

- Make sure your using the proper fiber type for you converter/runs (SM converter + multimode fiber = problems)
- Try swapping pairs at one end. You said you're doing Rx -> Tx and Tx -> Rx, try reversing on one side to see if it makes a difference.
- Verify the converters are working using a fiber patch cable between them.
- Try new patch cables, we run in to cables that you can see light through but won't pass data the odd time.

Eildor

terryfera wrote: »

Some things to check:

- Make sure your using the proper fiber type for you converter/runs (SM converter + multimode fiber = problems)
- Try swapping pairs at one end. You said you're doing Rx -> Tx and Tx -> Rx, try reversing on one side to see if it makes a difference.
- Verify the converters are working using a fiber patch cable between them.
- Try new patch cables, we run in to cables that you can see light through but won't pass data the odd time.

- I believe the converter does indeed do multimode.
- Tried every combination under the sun, hasn't made any difference.
- Have tried several different cables, tried cleaning them too... can't rule out dirt though.

About running a fibre patch between the converters... so I get the fibre cables and simply plug them from one converter to the other -- correct? Nothing plugged into the ethernet port, just simply going from one converter to the other. If the converter and cables are working should that result in the converter activity lights coming on you think?

networker050184

It depends on the type of converter. You will probably have to do some research as to the specific make/model to see what constitutes link up.

I found the link below. Might want to make sure you have the MM model if that's what you are using.

http://www.edimax.com/en/produce_detail.php?pd_id=298&pl1_id=9&pl2_id=37

terryfera

networker050184 wrote: »

I found the link below. Might want to make sure you have the MM model if that's what you are using.

Edimax ET-912+ Series - 100Base 10/100BaseTX To 100Base-FX Media Converter

To add tot hat also make sure that the fiber between the patch panels is the same type you are using for patch cables.

Eildor

networker050184 wrote: »

It depends on the type of converter. You will probably have to do some research as to the specific make/model to see what constitutes link up.

I found the link below. Might want to make sure you have the MM model if that's what you are using.

Edimax ET-912+ Series - 100Base 10/100BaseTX To 100Base-FX Media Converter

I think it's the 912MST+, which is listed as multi mode. I would have thought that if the converter was for single mode fibre it wouldn't take the connections I posted previously, no? Anyway, I'm pretty sure it is a multi mode converter but I'll double check.

Unfortunately there is no manual for this particular model on the Edimax website.

Eildor

terryfera wrote: »

To add tot hat also make sure that the fiber between the patch panels is the same type you are using for patch cables.

I don't know what kind of fibre is being used between patch panels, not sure they would know either to be honest. They do have fibre running in other parts of the building with this same setup and they seem to work fine, however we did run into a problem today that when one of the working fibre connections was unplugged and then plugged back in (we wanted to test some cables on the fibre that we knew was functioning) the lights on the converter wouldn't come back up; we did eventually get the lights to come back on but no one knows how... we unplugged the ethernet cable, and we switched the side of the fibre cable which was plugged from the fibre patch panel to the converter... so say it was white blue on one side and blue white on the other we flipped it so it would still be white blue and blue white (we just literally changed the side of the fibre cable we were using)... for some reason it worked, now like I said I know nothing about fibre but surely the side of the cable you use is completely irrelevant -- right?

vCole

Can you see a light on the end of the fiber? Try checking the fiber at each end point to see if you see the light. If not, something is either broken and/or not swapped properly.

Eildor

vCole wrote: »

Can you see a light on the end of the fiber? Try checking the fiber at each end point to see if you see the light. If not, something is either broken and/or not swapped properly.

We have shined a laser through the fibre patch panel and yes we do see light at the other side.