Ethernet Conduit

On Sunday 28 April 2013 12:22 F wrote in uk.d-i-y:

"Current applications running at 1 Gb/s are really pushing the limits of category 5e cabling."

That's complete and utter bollocks. Gigabit is within the stated spec. Yes, it's very clever how they do it. But it is not "pushing the limits" which makes it sound like it will fall over if a gnat farts.

Must be a company that's trying to sell Cat6a.

On Sunday 28 April 2013 12:45 polygonum wrote in uk.d-i-y:

On Sunday 28 April 2013 16:18 dennis@home wrote in uk.d-i-y:

On Sunday 28 April 2013 15:26 F wrote in uk.d-i-y:

What does "as well" mean? For the specified distance (90m on the installation cable plus 2x 5m patch cables and connectors=100m total) it is completely reliable.

Cat6a does not given any additional length for gig - still 100m.

On Sunday 28 April 2013 17:39 F wrote in uk.d-i-y:

Was it a certified installation? ie had it been tested (using TDR type testers, not "Maplin did I get the wiring the right way around" testers) and signed off by competant installers?

Definitely go for cat 6a which is gigabit and not 10/100 if you are going to all that effort.

If you are running your switch hub from the basement be aware of a good design would be to place the hub in the middle of the house and run off connection in a spider the hub should be the shortest distance from the incoming phone/cable. The shorter the distance the faster the connection.

This is also very important when copying computer to computer when speed is everything and not using internet.

A good idea a friend did while your at it is to wire a double socket and

I have a 50 metre or so length of cat5e which I'm sure isn't fully up to standards, I crimped it myself to get the exact length I wanted and to make it easier to thread the cable first. I has worked at 1000Mb/s ever since I installed it.

On Sunday 28 April 2013 22:46 hewhowalksamongus wrote in uk.d-i-y:

Once again for the gentleman who didn't read the thread:

Cat5e is gigabit for a range of 100m.

Cat6a is gigabit for a range of 100m Cat6a can do 10 gig for a range of 100m.

Cat6 is 100m at gig and 55/37m at 10 gig depending on environment.

Why wouldn't it be up to standards? Didn't you use the correct wire or plugs? I suppose it would be cat 5 as 5e needs tests done but is the same if both of them are done correctly.

For gigabit the duration of a (non-jumbo) packet is (1500 * 8) / 1,000,000,000 = 12 microseconds

The difference between the longest possible cable (100m) and the shortest possible (let's say zero) is (100 - 0) / (300,000,000 * 0.7) = 0.4 microseconds

So the most difference that cable length can make is 3%, and that's ignoring interpacket gaps, forwarding delays within the switch (if you're using one), the interrupt rate of the NIC, and the overhead of the operating system. So cable length is barely important at all ...

but do make sure you buy real Cat 5e, and not CCA/CCS (copper covered aluminium/steel), which are sold as cheaper equivalents, when they aren't equivalent.

When I moved in 13 years ago, I ran a pair of Cat5e to each room, used for network and phones.

If I was doing it now, on top of that I would add in loft, basement (if you have one), garage, kitchen (which I omitted), and you would want at least an extra pair (or more) to your entertainment centre location(s), and home-office/workshop.

I would say its totally irrelevant as the sliding window for data and acks, etc. allow for transmission delays several orders of magnitude higher before the data throughput is affected.

Yes, there are so many other factors that can delay the data (and none that magically speed it up) together they all tend to dwarf cable length (at the scale of a building).

Because I'm not perfect! :-)

As far as I know I did, however there are likely a number of minor issues with it:-

I've probably untwisted too much at the terminations.

It's likely that there are bends less than the specified minimum radius.

It's out in the open air with no extra protection (though the terminations are indoors), it runs from the house to a garage through some trees.

I've never been able to find plugs which specifically state that they are for either solid or stranded conductors so it's quite likely I have this wrong.

Quite, however what I was pointing out is that I believe that cat5[e] has quite a margin of 'performance' even when used at 1000Mb/s.

Not so likely, you have to go out of your way to get plugs for solid cable.

I was going to say that... but then I checked. Gigabit is half duplex, so the cable length (hence turn-round between sending a packet, running out of window, and getting an ack) is real. Probably not significant though.

Andy

The spec allows negotiating half duplex if both ends agree, but lots[1] of kit I've used only supports full duplex when using gigbit speed, both ends send and receive concurrently on all 4 pairs (each end cancelling what it's sending from what it sees on the cable to extract the other end's signal).

I wouldn't run more than a few ethernet cables in a trunk, I would site a switch on each floor.