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I have two places to connect. Let's call it, place A and place B.

On place A there is a Fortigate100D which has this kind of port;

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On place B there is a Cisco SF200-48 10/100 Smart Switch;

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I have made the 1km cabling with this cable;

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I think the cable is Single-Mode and the termination should be with SC. I also probably need an SFP device, but as I searched, I should use 1000BASE-LX for single mode fiber. The question is I didn't see any SFP device with 1 SC connection. I am perplexed right now and need some help.

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The yellow cable indicates single-mode fiber which is also necessary for a reach of more than a few hundred meters. The usual Gigabit Ethernet PHY for this is 1000BASE-LX, you're correct. (It's actually 1000BASE-LX10 for 10 km reach, the original 1000BASE-LX with 5 km reach is pretty much obsolete. You could also use 1000BASE-BX10 with single strands.) From the photo, the fiber is unterminated.

SFP modules use LC connectors as SC is too large to fit. Many fiber panels terminate with SC jacks, so you use SC-to-LC patch cables. Make sure you get single-mode patch cables as well.

LC SC LC versus SC duplex connectors (pictured with orange OM2 cable which is not what you need)

When buying transceivers, watch out for their brand compatibility - most devices only accept correctly branded transceivers: in your case Fortinet on the one and Cisco on the other side. The transceivers don't necessarily need to be original vendor's, there's a large market of compatible modules.

On the FGT-100D, note the shared TP/SFP ports - port 15 is already in use with twisted pair, so you'll need to use port 16.

  • The standard configuration is with duplex connectors, using two strands, one in each direction. (-BX/-BR use single strands with simplex connectors and higher speed,multi-fiber Ethernet mostly uses MPO connectors.) Isn't your cable terminated yet? You'll need to get a panel and have pigtails spliced on the fiber ends (or use the glue-and-polish method). – Zac67 Dec 29 '18 at 8:19
  • I don't have any fiber patch panels and if there is a chance to connect without patch panel I will go for it. I am going to buy sockets and SFPs after I am sure about the right tools. My cable goes as one, but when I terminate it with SC and convert it to LC with a patch cable, there will be two sockets right? So it can work as a Full Duplex? – Voliax Dec 29 '18 at 8:21
  • With your 4-strand cable you'd set up two duplex connectors in the panel, providing two LX-style connections. Note that "duplex" and "simplex" connectors indicate the number of strands only, Gigabit Ethernet or faster always works in full-duplex transmission mode. Fiber termination should be done by trained personnel, it's not easy and splicing equipment is pretty expensive. Don't do it without panel as it's very easy to damage the fiber or termination and you'll want to be able to swap the exposed cables easily. – Zac67 Dec 29 '18 at 8:25
  • Yes, I will call some professionals for the termination of the cable because I am not a Network Engineer but, as a System Administrator I just need to buy the right parts and I need to make sure it works. Now I can solve this problem with the information you have provided. I greatly appreciated your help! – Voliax Dec 29 '18 at 8:33
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I think the cable is Single-Mode

Looks like your cable is single mode (yellow jacket generally indicates singlemode) and has four fibers in it.

and the termination should be with SC.

Or LC.

Either way when terminated there will be four connectors on the end of the cable, one for each fiber. These connectors may or may not be joined into pairs using clips.

I also probably need an SFP device, but as I searched, I should use 1000BASE-LX for single mode fiber.

1000BASE-LX (or LX10 which is basically the same, just with a longer maximum range) runs over a pair of single mode fibers, so your transciever will have a pair of connectors on it. You also get 1000BASE-BX which runs over a single strand of single mode fiber.

Note that it is necessary to cross over transmit and receive between the two transceivers. With LX this is done by crossing over the fibers. With BX this is done by using an "upstream" transceiver at one end of the link and a "downstream" transceiver at the other.

The question is I didn't see any SFP device with 1 SC connection. I am perplexed right now and need some help.

Due to space constraints SFP modules use LC rather than SC connectors.

I don't have any fiber patch panels and if there is a chance to connect without patch panel I will go for it.

A patch panel isn't absolutely essential but it is generally considered a very good idea. The individual strands of infrastructure fiber have very little protection while patch cables have separate Kevlar reinforcements for each individual fiber. A fiber patch panel should provide a place to secure the reinforcement of the infrastructure cable and then provide protection for the individual fibers as they pass to the couplers on the front of the patch panel.

The patch panel also means that if/when in the future you change to equipment that has different connectors you can simply replace the patch cord.

I am going to buy sockets and SFPs after I am sure about the right tools.

My advice would be to get the termination of the fiber done by a specialist and let him supply the connectors and patch panel. Learning to terminate fiber is a specialism in itself.

  • This answer is awesome, thanks for giving your time! I will buy LC connectors to terminate the cable directly. Now I only need to find out which SFP I should use on Fortigate 100D and Cisco SF200-48. If you have any idea I would love the hear it. – Voliax Dec 30 '18 at 9:04

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