Great open barrel crimper for Molex terminals

Yes. An iron rice bowl: .

Joe Gwinn

Does this apply to:

2) Network cabling in commercial or apartment buildings?

When our house was being expanded, I ran some thicknet ethernet cable (picked up big spools of it at a hamfest) between several places where networked computers are sometimes set up. Had I known about

Hmm ... also -- does it apply when running ethernet through fiber optics? No wires there at all! No excuse for needing someone who is accustomed to wiring voltages around. :-)

And how about today's WiFi?

Granted, I have a friend with an old house where it does not work well at all. The walls are not drywall, but rather real plaster over metal mesh. But I can't imagine an electrician knowing enough about that to even diagnose the problem. :-)

Enjoy, DoN.

Gotta "protect the public", you know.

Best regards, Spehro Pefhany

Depends on the local laws, I suppose. One should not be expecting a real technical rationale.

Hmm. This could be fun! Well, it looks like a wire....

Clearly, does not apply.

Eight or nine years ago, I paid an electrician to install the CAT5e cable from basement to my wife's office on the second floor, and I will say that the electrician and his helper earned their pay on that one. It's an old house, with wood lath plaster and strategically-placed bricks as fire-stops. It took hours, and they were working all the while.

I then terminated and connected the installed cable. It works just fine.

Installing that wire probably cost what a full WiFi setup would have cost, but once installed the wire just works, needs no sysadmin effort, has no security drama, and has far greater data capacity than the WiFi of the day. Only recently have wireless LANs even approached the theoretical datarate of a CAT5e wire. In practice, wireless LANs rarely achieve anything like the capacity of a cable.

If I ran cable today, it would be CAT7, which supports gigabit datarates, far exceeding any likely wireless LAN technology. The CAT7 wire is expensive to be sure, but installation costs will swamp the wire cost.

But the current 100 megabits per second is more than sufficient.

Actually, the best thing to install is plastic conduit, if one has the opportunity to do it reasonably easily, like if the walls are already open for some other reason.

I recall lots of ads from various wire manufacturers touting their latest (fastest, expensive) kinds of cable, saying that companies should buy the better stuff even if not strictly needed today, as "future-proofing". But, conduit is the true "future-proofing", as one can always upgrade the wire within, and easily. Nor does one need to guess which direction the technology will go and which wire it will need. For some reason, the ads didn't mention the conduit option.

Joe Gwinn

NJ has an extortion scheme where you can "apply" for an exemption for low-voltage network & telecom wiring. This self-certification costs $120. In over 30 years of doing this work, nobody has ever asked me for a certificate. Maybe I'll get one someday.

Regarding Iggy's original post about the crimper - there is simply no excuse for not doing it right. The tools are expensive, but having the right crimper for the right terminal for the right wire is the ONLY way to ensure a reliable termination. "Pulling" on the terminal after crimping is pretty subjective. When I was in production engineering, we spent a lot of time and money measuring crimps with specialized micrometers and pulling on them with calibrated scales.

OTOH, when I was at AT&T, I was impressed by the union electricians I worked with on DSLAM installations. They had the right tools for the job and knew how to use them, in contrast to some of the equipment they were installing, some of which had crimps that looked like they were done with vise-grips.

In Connecticut if you get paid to touch premise wiring you need the license unless you work for the phone company, which has a specific exemption. That includes network cabling outdoors, network cabling in commercial or apartment buildings, and home wiring. Homeowners in most areas can do their own wiring subject to permitting and inspection.

The law is specific about the definition of "electrical work" and it looks like fiber is exempted. So is wiring under 24v used for controlling lawn sprinklers--if you have a network-aware law sprinkler attached to your LAN does that mean that you're exempt?

The definition is: (2) "Electrical work" means the installation, erection, maintenance, alteration or repair of any wire, cable, conduit, busway, raceway, support, insulator, conductor, appliance, apparatus, fixture or equipment that generates, transforms, transmits or uses electrical energy for light, heat, power or other purposes, but does not include low voltage wiring, not exceeding twenty-four volts, used within a lawn sprinkler system;"

One could argue wifi either way.

Never. 802.11N has a theoretical maximum throughput of around 450 Mb/sec, CAT5E handles 1000.

CAT 5e supports gigabit just fine. You don't need CAT7 for, well, anything. 10 gig Ethernet runs on 6A. 7 is something that the cable manufacturers want you to think you need, but you don't unless you have unusual circumstances.

If it's not, you can get gigabit NICs for 20 bucks.

And it never was. CAT5 needed to be recertified to 5E to run gigabit (most CAT5 installations pass 5E, but they weren't tested to it until it became part of the requirement). CAT6 didn't meet the 10G spec, leading to 6A. 7 is a solution in search of a problem.

I was asking in particular about the Connecticut situation which J. Clarke mentioned.

Might be fun to take it to court. :-)

Sounds like you are thankful that *you* did not try to do it yourself. :-)

Of course.

Of course. I've got a wireless bridge running to a friend's house across the street and down one house -- using circular waveguide antennas which I machined up. Encryption enabled, good aggressive firewall on each end, and all logins from one side to the other via ssh.

Certainly. I'm running my home directories from a server on another machine, and the speed is quite adequate for most things. If I want to run find(1) on the home directory, I do that on the server itself, of course.

Hmm ... specifically plastic? Is there a problem running twisted-pair ethernet in close proximity to a metal surround? I know that some of the network wiring we installed at work was shielded four twisted pair cable. Or is plastic conduit simply less expensive?

:-)

Enjoy, DoN.

Translate to "protect the union" Gerry :-)} London, Canada

That's pretty well the way it works. You can't get in the club unless you do a two year apprenticeship or show 6 years "equivalent experience", which would presumably be military or telco.

Absolutely. I've pulled my share of wire over the years, and old houses are the worst.

I'm assuming that you added the waveguide antennas to standard wireless LAN equipment.

CAT5 and CAT5e are not shielded, so running in steel conduit may cause unexpected losses and reflections. But I have not tried this. CAT7 is shielded, so running in steel conduit would have no effect. I don't recall if CAT6 is shielded, but I think it is unshielded. J.Clarke may know more.

But my reason for plastic was economic, not technical.

Joe Gwinn

Definite iron ricebowl issue.

Given that radio communications is a major use, and yet isn't mentioned, it ought to be an easy argument.

And the backup argument would be that obviously the electricians need to obtain radio transmitter licenses from the FCC before touching any such equipment.

I was being nice. And hardwire links achieve a far greater fraction of their theoretical throughput than wireless links.

If I recall, the rationale for CAT7 is to carry 40/100 Gigabit ethernet short distances within datacenters, the theory being that optical was too expensive and not needed for such short links. Don't know if the market agreed.

In many systems I have worked on, we must use shielded twisted pair such as CAT7 to ensure that the ethernet works despite heavy EMI. The alternative is fiber, and cable is far easier for links between adjacent cabinets and/or to devices not supporting fiber.

And CAT7 is just dandy for carrying LVDS signals. This may not be what the wire companies dream of - volume far too low.

Yep.

Yep.

As discussed above.

Joe Gwinn

Cat 6 & 6A are unshielded. So far all of the successful X-base-T cabling has been unshielded.

I can believe that.

Right. A bit more directionality and gain -- to improve our signal during nasty weather, and to somewhat reduce people in a position to snoop on the signals -- even with all the protection in place.

O.K. That I can accept.

O.K. Out of curiosity -- how long does it take a motivated mouse to gnaw through the wall of a plastic conduit? (Motivation could be fingerprints from the sandwich the installer was eating. :-)

Enjoy, DoN.

Turns out that CAT6 is unshielded, so CAT7 it would be.

Hmm. I've never heard of this happening, and lots of plastic conduit and pipe is used. Mice are lazy too. They would lick the conduit clean before trying to gnaw through.

I assume that part of the conduit development process was to pick a plastic formulation that does not taste good to rodents. It's certainly a big deal for wire and conduit intended for direct burial.

Joe Gwinn

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