Advice on shielded cat 5e installation

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sajunky

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Gnome said:
Why?
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I don't like 3-point termination, it increase possibility of ground loops which should be avoided in first place. Leaving one side of the cable floating do not degrade signal to such extend that we should worry much.

Besides, some expensive equipment do not terminate cable shield to the device chassiss, but to the differential I/O transformers. These are separate ground points in order assist installation where ground loops give problems.

Once again, this off-topic, it doesn't apply to the OP.
 
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infscrtyrisk

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sajunky said:
Stop posting sales speech.
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Whilst I am leaning towards principles which I hold dear on this issue, I think that we should encourage those who challenge things, in the name of science. The "teachings of Aristotle" sometimes need a Galileo.

Give the man a break.
 
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sajunky

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infscrtyrisk said:
Whilst I am leaning towards principles which I hold dear on this issue, I think that we should encourage those who challenge things, in the name of science. The "teachings of Aristotle" sometimes need a Galileo.

Give the man a break.
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Well, the 'man' is posting the same sales speech PDF second time. The real man do not do it.
 
Gnome

Gnome

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sajunky said:
I don't like 3-point termination, it increase possibility of ground loops which should be avoided in first place. Leaving one side of the cable floating do not degrade signal to such extend that we should worry much.

Besides, some expensive equipment do not terminate cable shield to the device chassiss, but to the differential I/O transformers. These are separate ground points in order assist installation where ground loops give problems.

Once again, this off-topic, it doesn't apply to the OP.
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As I said above, ground loops is of no consequence to ethernet. There are multiple sources for this, but this guy put a decent response on the topic:
https://networkengineering.stackexchange.com/questions/6773/stp-termination-and-grounding
 
Gnome

Gnome

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sajunky

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Gnome said:
As I said above, ground loops is of no consequence to ethernet. There are multiple sources for this, but this guy put a decent response on the topic:
https://networkengineering.stackexchange.com/questions/6773/stp-termination-and-grounding
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In the link above you get advice to avoid ground loop (even the same person claims it won't affect Ethernet). So please read carefully your links before posting.

You entered this discussion showing example of your installation, which I confirmed it was correct. Then you asked why do not do 3-point termination, so I explained why is wrong.

Now you are trying to defend 3-point termination, giving the above link as an example. You are trying to force different practice on others, use it in your house in first place! :)

My position on ground loops is very clear:

1. It doesn't affect much of Fast Ethernet, but you don't use shielded cables on Fast Ethernet home, do you?.

2. It affects Gigabit Ethernet. A reason I explained in my previous posts, but you didn't read or understood correctly. Gigabit Ethernet has introduced some form of digital signal processing (DSP) for eliminating crosstalk between pairs of the same cable. DSP is sensitive to the noise and common mode distortions in particular. So the low frequency of ground loops do matter.

3. It will affect 10Gbit Ethernet more than Gigabit, as DSP is fully implemented.

4. Ground loops will likely destroy your equipment during lightning strikes.

While I don't like ground termination on one side I prefer it in preference of creating dodgy 3-point termination, in all cases where equipment is powered by different distribution boxes or for outdoor installations where ground can raise during lightning.

I also strongly oppose using shielded cables in home installations. For Gigabit Ethernet Cat5e is sufficient. For 10Gbit Ethernet there is Cat6A UTP cable (if you want to be future proof). Cable manufacturers force shielded solution, as it costs more (for the consumer) and it is easier to certify STP cable for alien crosstalk than UTP Cat6A. You don't have much of alien crosstalk home, do you? :) So use Cat6A UTP.
 
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Gnome

Gnome

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sajunky said:
In the link above you get advice to avoid ground loop (even the same person claims it won't affect Ethernet). So please read carefully your links before posting.

You entered this discussion showing example of your installation, which I confirmed it was correct. Then you asked why do not do 3-point termination, so I explained why is wrong.
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The reasons given for avoiding ground loops had nothing to do with signal degradation however. Everything I've read thus far contradicts what you say. Do you actually have some links for your information? I couldn't find anything about it.


sajunky said:
My position on ground loops is very clear:

1. It doesn't affect much of Fast Ethernet, but you don't use shielded cables on Fast Ethernet home, do you?.

2. It affects Gigabit Ethernet. A reason I explained in my previous posts, but you didn't read or understood correctly. Gigabit Ethernet has introduced some form of digital signal processing (DSP) for eliminating crosstalk between pairs of the same cable. DSP is sensitive to the noise and common mode distortions in particular. So the low frequency of ground loops do matter.

3. It will affect 10Gbit Ethernet more than Gigabit, as DSP is fully implemented.
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Do you have links, I thought you may have a point, so I read about how GMII (The PHY for GbE) works. Then looked for data related to its susceptibility to the conditions you describe, again, couldn't find anything.

sajunky said:
4. Ground loops will likely destroy your equipment during lightning strikes.

While I don't like ground termination on one side I prefer it in preference of creating dodgy 3-point termination, in all cases where equipment is powered by different distribution boxes or for outdoor installations where ground can raise during lightning.
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Yeah I'm not really going to argue about going outside. I personally ran my outside cables using fiber (I'm in the US multiple times a year and fiber -> GbE-X converters are like R400 for a pair and fiber is cheaper than ethernet cable).

We are talking about grounding in a home and using ground wire at every termination point referenced to the same ground.

sajunky said:
I also strongly oppose using shielded cables in home installations. For Gigabit Ethernet Cat5e is sufficient. For 10Gbit Ethernet there is Cat6A UTP cable (if you want to be future proof). Cable manufacturers force shielded solution, as it costs more (for the consumer) and it is easier to certify STP cable for alien crosstalk than UTP Cat6A. You don't have much of alien crosstalk home, do you? :) So use Cat6A UTP.
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I bought this stuff while I was in the US, I don't quite buy that it is lower quality because they sell CAT6a UTP that is actually cheaper (same brand). And the specs are actually lower in terms of rated cable frequency.
 
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sajunky

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Gnome said:
I bought this stuff while I was in the US, I don't quite buy that it is lower quality because they sell CAT6a UTP that is actually cheaper (same brand). And the specs are actually lower in terms of rated cable frequency.
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So you bought low smoke stuff, it looks a higher grade, but low smoke is lower quality by definition than a standard grey cable. .LOL.

And of course specs are better than Cat6A UTP brand stuff. It is normal. Many people buy for specs and what it looks a higher grade.
 
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