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I am trying to get an Gig-E network between two buildings that are approximately 260 ft. away. While some TRENDnet switches failed to be able to connect to each other over Cat 6 at that distance, two Netgear 5-port Gig-E switches do so just fine. However, it still fails after I put in place APC PNET1GB ethernet surge protectors at each end before the line connects to the respective switches. So I find myself wondering if I simply need to find a better surge protector that doesn't degrade the signal as much (if so, what kind would you recommend?) or if I should give up on copper and use fiber between the buildings.

If I opt to go the latter route, I could really use some pointers. It looks like LC connectors are the most common, but I keep running into some others as well. A media converter on each end seems like the simplest solution, but perhaps a Gig-E switch with an SFP port would make more sense? Given a very limited budget, sticking with my existing copper seems best, but if it is bound to be a headache, a 100 meter fiber cable is something I think I can swing cost wise.

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I'd go for fiber, but I still remember the constant problems I had with surge protectors: I had roughly half of the length of wire you have hanging between buildings on a support wire and I was always replacing burnt surge protectors - during storm season sometimes even once a week. Ended up scrapping the whole idea of running that connection on copper. –  c2h5oh Sep 24 '12 at 2:35

4 Answers 4

While Ethernet runs should extend up to 330 feet, as you've found many pieces of cheap equipment don't meet that specification. The most reliable solution you'll find here is to run fiber from one building to the next. It provides inherent galvanic isolation, so there's no need for surge suppressors (which probable don't work the way you think they do in the first place) or any potential attenuation problems.

If your current gear can accept SFP fiber modules, that will be the cheapest and most flexible route. Media converters tend to be of cheaper quality, and I avoid them at all costs.

Be careful to get SFP modules rated for your applications:

  • Distance: the 100m distance you'll be covering; most are rated for this, but there are different modules for different distances (Usually modules support either "Short Range" for Multi-Mode cable, or "Long Range" for Single-Mode cable; you'll want the short probably).
  • Connectors: SC, square connectors, are the most common in generic applications like yours. You can use anything you want, but SC is the "default" for things like this.
  • Fiber Type: You'll want OM2 50/125 µm Multi-Mode Fiber (It's orange, and very easy to find; especially with SC/SC connectors attached too).

The module has to support this configuration. It's extremely common, so it should be easy to find these modules... But make absolutely sure the module is rated for the above! Get two identical modules too, do not mix and match unless they're being provided by an expert who has a guarantee worth more than the paper it's written on that they'll work together.

PS> I know the warnings seem a bit scary, but Fiber is easy stuff when you know what will bite you...

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"Do not stare into laser with remaining eye." –  EEAA Sep 24 '12 at 4:24
    
Thanks for the helpful guidance! Right now, I don't have any SFP supporting equipment. Do you have any recommendations for someone starting from scratch on this point? –  Timothy R. Butler Sep 24 '12 at 6:10
    
We try not to do product recommendations on Stack Exchange sites... But you could pickup a pair of ProCurve 2824 (part# J4903A) on eBay for less than $300 each; and pickup ProCurve J4858C (or compatible) SFP modules for <$60 each. Note this SFP uses LC connectors. So you'd be looking for an OM2 LC/LC 100m cable (should be <$150 on the net). Also OM3 and OM4 would work just fine, they'll just be more expensive. There are plenty of other options, I just picked this setup as you were already talking about switches at either end, it's fairly cheap, and ProCurve has transferable lifetime warranties. –  Chris S Sep 24 '12 at 14:00
    
Thanks for the suggestions. How compatible are SFP modules between product lines? For example, if on one end a media converter makes more sense and on the other, a switch makes sense, if I find an SFP module brand that claims to be compatible with the HP ProCurve switch and a TP-Net media converter, would that be a workable solution? Or should I stick to not only the same SFP modules but also the same brand for the devices the SFP modules are inserted into? –  Timothy R. Butler Sep 24 '12 at 20:19
    
That may work... that is SFPs/Converters working on the same wavelength, and same protocol will inter-operate with each other over the fiber. Making sure both are exactly the same in these regards is a bit more tricky. If the products have good spec, you can simply compare them and see. In particular look for the wavelength measured 'nm' and the protocol spec '100BaseTX' or '1000BASE-SX' (these two are 100% incompatible with each other for example!). –  Chris S Sep 24 '12 at 20:24

It's generally not recommended to run copper directly between buildings as individual structures tend to be separately grounded (or earthed, if you prefer). Even a relatively small difference in potential can destroy equipment and even create a hazardous condition for people working on the equipment.

Perhaps more to the (immediate) point connection integrity can be significantly degraded - especially if the method/path used to run the cable between buildings is subject to excessive interference. This can manifest as poor performance even on in-spec runs.

The right way to do this is with fiber. Distance limitations cease to be a practical issue, electrical isolation is assured and the network will perform as it should. Go for a simple media converter or a switch with native capability for fiber ports - either will be fine for your application. If you don't have need for additional fiber capacity, the media converter is probably the cheaper/less intrusive mechanism.

PS - Don't be concerned with what "ought" to work. The distance certifications on network media exist for a reason, a reason which will become abundantly clear when a previously working over-spec installation ceases to function for no apparent reason. Saving a bit of money up front doesn't seem like much of a deal when whole buildings are cut off.

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Thanks -- the separate grounding matter is interesting. As to being overspec, so far I believe we are under the spec, which is why I thought it should work (and it does, save for when I try to provide surge protection). The big issue, so far, is that if I have the incoming line of surge protection, it quits working. But, fiber does seem to make sense. Are most media converters pretty much the same or is there a rule of thumb for picking out a good one? –  Timothy R. Butler Sep 24 '12 at 6:07
    
Media converters should be basically the same. On balance I'd tend to prefer units with pluggable optics (i.e. SFP-based) to provide a bit more flexibility but this is by no means required. I wouldn't be opposed to picking a cheaper unit, for example, but would recommend keeping a spare around regardless. –  rnxrx Sep 25 '12 at 0:51

You might have a look at Ubiquiti's line of products, specifically their airFiber solution.

Could be over kill for a mere 260ft, or not what you're looking for specifically... but I've been using some of their products lately and they're pretty awesome. Fun to check out at least!

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+1, I've been impressed with Ubiquiti's product line, and they make sense for this situation as well. –  jrg Sep 24 '12 at 13:48
    
Thanks! I'll look into that some more. I've looked just briefly at their products in the past... –  Timothy R. Butler Sep 24 '12 at 20:16

Simple kludge: Put the "Netgear 5-port Gig-E" at each end, and directly connect those to, and only to, the desired TRENDnet switch.

Technical cable length limit is 100m/328ft. Some folks have had luck getting runs of 200m. Ethernet surge protectors aren't the right tools for the task of amplifying the signal or squelching noise. Assuming no impediments to the cable run (notably interference generating sources), would suspect inadequate cabling and/or below standard termination.

Fiber is the standard. If budget is a constraint, simple copper should suffice.

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Thanks! My goal with the surge protector was to protect from surges, rather than amplify (it works without amplification of any sort, but there seems to be a lot of signal loss using the surge protectors). So, are you suggesting using the Netgear switches in lieu of surge protection, essentially as sacrificial switches? –  Timothy R. Butler Sep 24 '12 at 6:05
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Yes. It is a kludge. Situation still has a feeling the cable itself is less than optimal as those Netgear switches are in the $50 range (i.e., very inexpensive). –  RandomBit Sep 24 '12 at 13:50

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