[Server-devel] [UKids] Lightning kills underground Ethernet too; PoE wiring/voltages non-trivial!

[Samuel Greenfeld]

On Tue, Jan 12, 2016 at 4:55 AM, John Gilmore <gnu at toad.com> wrote:

> The cheapest of those fiber-enabled switches still cost about US$300
> the last time I looked.  The GBICs cost about $50 to $100 at best.
> The fiber cable itself is finicky and ideally you would buy it from a
> supplier who will cut it to the right length and put the right
> connectors on it for you (because doing this in the field requires
> custom equipment, trained personnel, and is slightly hazardous with
> tiny bits of glass fiber that can get under your skin).  Fiber cables
> can't be bent as much as cat5 cables (or the glass fibers inside
> break) so you have to take some care installing them.  Unfortunately
> there are no standards for fiber connectors, or rather there are
> dozens, so you'd have to pick one connector type (e.g. "LC"
> connectors) and get the cable and the SFP that have those connectors.
> There are half a dozen 1000Base-something standards for fiber
> ethernet, too, for different kinds of fiber cables and different
> distances, so you have to specify which standard your SFP's will use.
> You may need a pair of cheap attenuators too, if your fiber run is
> short (to reduce the intensity of the light in the fiber).  Compared
> to just getting cat5e or cat6 cables and plugging them into a cheap
> and standard switch, fiber is much more complicated and expensive.
>

It depends on the port count and how managed it is.

Netgear has at least one semi-fancy switch (8 port PoE+2 port SFP) for
$150.  But being a PoE switch, it comes with a pretty hefty (24 or 48 Volt
IIRC) power supply.

SMC appears to have a similar switch without POE available for ~$110 on
Amazon.

I only have experience with the Netgear switch.  Third party GBICs can run
$25-$50 each depending on the manufacturer & source.



> > > Cables routed inside of walls/vents/etc. also often have to be one of
> a
> > > few special types for fire safety and other reasons.
>
> These are called "plenum rated".  Their special property is that when
> they burn (e.g. when the building catches fire), they don't release
> toxic gases that will hurt the people/kids who are breathing the air
> nearby.
>

I am aware of plenum rated; but I've also seen terms like "riser rated"
(not as strict as plenum?) and similar tossed about.

In all cases installation should be done in accordance with the local
building codes, if there is such a thing in the area.
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