Protecting 1Gb Ethernet From Lightning Strikes

Eric Kuhnke eric.kuhnke at
Thu Aug 15 01:54:03 UTC 2019

Another copper cable considered a "gold standard" for outdoor shielded +
9th ESD drain and ground wire, intended for long term rooftop and tower
installation is Shireen. There's a variety of types.

On Wed, Aug 14, 2019 at 6:30 PM Brandon Martin <lists.nanog at>

> On 8/13/19 2:32 PM, Warren Kumari wrote:
> > This probably won't fully solve your problem, but I run a bunch of
> > Ubiquiti access points and similar -- I suffered a number of lightning
> > related outages, and then started using their TOUGHcable -
> >
> While ToughCable isn't bad (especially for the price), if you want
> something REALLY durable both physically and against electrical
> transients, I've been very happy with Primus C6CMXFS-1864BK.  It costs
> quite a bit more than the ToughCable but has real water blocking (which
> means you had better be prepared to deal with "Icky Pic"), heavy
> shielding with drain, meets or exceeds CAT6 (which means you can push
> gigE a bit beyond 100m pretty reliably if you've got a tall tower or a
> hut far away from a tower base), and has 23AWG wire so PoE, especially
> Ubnt's crummy 24V passive POE, can go farther, too.
> Be warned it's a bear to terminate.  In addition to the waterblock, the
> cable diameter is too large for typical crimp-on RJ45 ends.  You have to
> either use special ends (which Primus sells, among others) or terminate
> it to a punch block which, while not usually a problem in a hut, is
> often problematic up on a tower.
> Ubnt also makes an outdoor fiber media converter I've found useful for
> "small cell" style wISP deployments where I can drag my own fiber to the
> tower/pole and don't want/need a hut or enclosure at the base.  Part
> number is F-POE-G2.  That'll let you get your power and signal
> separated.  I do wish they'd just put SFP slots in their radios, but at
> the price they sell them for, I guess I can't complain too much.  I'd
> put real 802.3af/at PoE higher on the list of wants, honestly.
> As to actual surge protectors, I see there have been some other
> suggestions in the list, and I'll defer to them.  I've personally had
> decent luck with just making sure the Ubnt passive POE injectors (which
> I need since I don't usually use their switches) are well grounded to be
> mostly sufficient (along with the tower and hut having proper grounding
> infrastructure).  I've not lost any radios, though I've had some lockups
> requiring power cycle after nearby lightning strikes on some of the
> lower end WA based platforms.  The XC based platforms seem hardier.  My
> sample size isn't huge, though.
> I'm usually of the impression that, unless you've got carrier (cellular
> or committed-rate microwave) class wireless gear on the tower or
> aggressive SLAs you have to meet from a wireless PoP, it's probably
> cheaper overall to just take reasonable precautions against lightning
> than it is to try to make things handle a "direct" strike.  Figure in
> the wISP world, tech moves so fast that you're having to put new things
> on the tower at least every 3-5 years anyway, so as long as an
> unscheduled trip up to the tower doesn't cost you $ARM+$LEG, it's
> probably easier to just take a lightning strike that fries everything
> due to extreme proximity as an unscheduled upgrade than the try to
> handle it electrically.
> "Nearby" strikes, static, electrical transients on your utility line,
> etc. are a different matter.  Those you can economically protect against
> i.e. the protection will not cost as much or more than the gear and
> service you're protecting.
> --
> Brandon Martin
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