What type of fiber optic cable and termination should be used for temporary outdoor connectivity at an event (UPC vs APC)?

Question

We are coordinating an outdoor event for a student contact with the International Space Station via ARISS. We will need internet for video streaming, and the nearest building with internet is 500 feet (152.4 m) away, so fiber optic seems like the best option. I know-point-to-point wireless is a possibility, but for real-time streaming and audio we do not want to risk interference and packet drops.

I was thinking of using a single-mode LC-to-LC fiber with a RJ45-to-LC-SFP media converter, but thought it would be prudent to ask here, and see if there are best practices to follow. The endpoints will be dry, but the run itself could get rain. There will be no foot-traffic where the cable is run (or, if there is, we will put hard foot traffic bridge over it).

I am considering custom 500' fiber cables terminated, but I wasn't sure what to put on the ends. Mostly I'm curious about:

• UPC or APC termination?
• Do either of UPC or APC require special GBICs?
• Other considerations?

Answer 1

If you have a way to keep the fiber protected/safe from feet and other dangers, it should be fine to use a simple pre-made patch cable. Personally, I would order 2 just in case of an issue with the first one.

As for the termination and equipment, you need to make sure everything matches. To keep it simple, use UPC termination, that is by far the most common in most applications outside of permanent service provider networks. Most SFP transceivers will be for UPC terminations and you will be able to tell the APC ones from their green markings (same with APC terminated cables, they have a green connector housing usually).

Single mode (OS2) is fine. Make sure your SFP transceivers are for Single Mode (SM, LR or similar in the model, and 1310 nm wavelength or occasionally 1550 nm). You simply need matching transceivers on each end as long as your equipment will work with them. Some brands of switch will want a matching brand transceiver but there can be configuration options to disable that requirement. If you are using media converters at both ends of the fiber, almost any transceiver of the right type and speed will work as long as they all match.

The media converter will determine the supported speed of the links, and the transceivers need to match (1 gigbit transceiver for a 1 gigabit media converter connected to a 1 gigabit switch port, etc.). LC connectors will be the most common option for SFP transceivers but there are media converters that use SC type connectors for 1 gigabit links (some use GBIC, some have an integrated transceiver).

That should be about it. It's quite easy to setup. If the link doesn't come up on your first try, make sure to try 'rolling the cable' which means to swap the fiber connectors on one end (RX to TX or vice versa).

Answer 2

Fiber is the right choice - just protect it properly.

For that distance you can use either multi-mode fiber with 1000BASE-SX transceivers or single-mode with 1000BASE-LX ones (I guess gigabit is the obvious choice).

UPC or APC doesn't matter technically, but APC is only useful for passive, single-strand networks. All -SX/-LX (duplex) transceivers use UPC (PC/SPC/...), so just go with that.

Answer 3

I was thinking of using a single-mode LC-to-LC fiber with a RJ45-to-LC-SFP media converter,

A few things to be aware of.

The first is single mode verses multimode. Single mode fiber is usually cheaper and can support longer distances, but the transceivers/media converters are more expensive.

The second is, that unlike copper Ethernet where nearly everything is multi-speed, fiber stuff is often only single speed. You need to make sure all your components run at the same speed and use the same type of Ethernet.

The third is the physical construction of the cable. There are different types.

"patch cable" has separate reinforcements for each fiber. So the fibers can be separated without losing the reinforcement. It's usually used for short runs, for example from a switch to a patch panel, though I have seen longer runs of it in some datacenters. I wouldn't consider it ideal for outdoor use though.

Infrastructure cable on the other hand has reinforcement for the cable as a whole, but once the individual fibers are split out they have no reinforcement. There are many sub-types, armoured vs unarmoured, tight buffer vs loose tube and so-on, but for your application I don't think that matters much.

You probably don't want to get involved with terminating fibres yourself, so your best option is probably to buy it pre-terminated. Pre-terminated cables normally ship with a gland and a protection sleeve. The gland is attached to the reinforcement in the cable, and then the protection sleeve is screwed to the gland, protecting the individual fibers and providing a safe pull point.

Infrastructure cables usually come with at least four fibers, so you have some spares in the event of a fiber breaking.

You need to think about how you are going to protect the fibres after the protection sleeves are removed. In a datacenter this would typically be done by using a patch panel with a tray or box on the back to which the gland can be attatched.

For a single link in a temporary setup that is probably not the most practical setup, but you should still think about what you will screw the gland to, and how you protect the fibers between the gland and whatever they are plugged into.

The transmit side of one transceiver or media converter must be connected to the receive side of the other. If you are using duplex patch cables, this normally happens automatically. However if you are using infrastructure cable, you are likely to have to take account of this yourself.