Long network cables

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#2348508 5-Nov-2019 16:03

If you are pulling cables, if you kink it, it's stuffed.
Don't try to straighten it out and pretend it didn't happen, cut it at the kink and start again.

Haha! Installers would waste a butt ton of cable of that was the case!

Obviously you don't want to kink it on purpose and need to take care, but it's not an issue if it gets a bit of a kink in it.

cyril7

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#2348509 5-Nov-2019 16:07

Regarding kinking it, this happens all the time, fortunately you can massage it out, I have for a test after massaging a cable stripped the sheath and visually checked and confirmed the pairs showed no sign of splitting (which is the issue from kinking, if the cores of the pair splay the impedances rises and causes reflections) I then tested it with a DTX, passed without issue.

But its best is you take care and dont kink.

Cyril

Dugimodo

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#2348511 5-Nov-2019 16:11

Kinking the cable potentially adds some loss and maybe crosstalk by distorting the twist and the lay of the pairs inside the cable. In an extreme case it can damage the actual conductors or even break them.

It should be avoided, but again for short runs it's less likely to matter. If it's a bad kink cut it out and start again, if it's only minor maybe just try it and see most likely it'll work just fine.

AKT

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#2348536 5-Nov-2019 17:54

Thank you all for your informative responses. All a great help. So just so I get this right I should.

1. Use solid cable if possible

2. Try not to kink it.

3. It's behind a wall so I don't care about the colour (fortunately)

4. Buy Cat6 cable (I want the best for future proofing and the different in $ is nothing compared to the cost of having the wall done) - I may have missed something here so correct me if I am wrong.

5. Not put my electronics in the roof space (I wasn't planning on it but the thought did cross my mind so I will avoid this)

6. Don't worry about length as it shouldn't degrade the signal unless I get past 50-100m which is unlikely

7. Buy some switches to distribute it once it gets upstairs

8. Run it away from the mains cabling 300mm if possible (this is easy to do but I may not have done it so thanks!)

Let me know what I missed

Andy

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#2348836 6-Nov-2019 08:44

That's about it.

Oh - run more than you think you'll need. You will need them.

mdooher

Hmm, what to write...
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#2348840 6-Nov-2019 08:52

AKT:

Thank you all for your informative responses. All a great help. So just so I get this right I should.

1. Use solid cable if possible

2. Try not to kink it.

3. It's behind a wall so I don't care about the colour (fortunately)

4. Buy Cat6 cable (I want the best for future proofing and the different in $ is nothing compared to the cost of having the wall done) - I may have missed something here so correct me if I am wrong.

5. Not put my electronics in the roof space (I wasn't planning on it but the thought did cross my mind so I will avoid this)

6. Don't worry about length as it shouldn't degrade the signal unless I get past 50-100m which is unlikely

7. Buy some switches to distribute it once it gets upstairs

8. Run it away from the mains cabling 300mm if possible (this is easy to do but I may not have done it so thanks!)

Let me know what I missed

Andy

If you have alarm cable in your ceiling do not run the data cable anywhere near it. .... Why? because it induces so much noise that the data needs to re-transmitted over and over again. it has the apparent effect of slowing down the connection. This is particularly bad with Paradox alarms.

Some installers have no idea about this. One of the problems is that even if the cable is tested for transmission speed with the best of gear they do that before the alarm system is commissioned and the interference doesn't show.

Matthew

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#2348852 6-Nov-2019 09:35

mdooher:
If you have alarm cable in your ceiling do not run the data cable anywhere near it. .... Why? because it induces so much noise that the data needs to re-transmitted over ad over again. it has has the apparent effect of slowing down the connection. This is particularly bad with Paradox alarms.

Some installers have no idea about this. One of the problems is that even if the cable is tested for transmission speed with the best of gear they do that before the alarm system is commissioned and the interference doesn't show.

This
Alarm system cables are notorious for spraying RF interference around.
I don't know why and I don't know why they don't use better gear and/or better cables, but "it's always been this way". Sigh

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Zeon

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#2348857 6-Nov-2019 09:52

PolicyGuy:
mdooher:

If you have alarm cable in your ceiling do not run the data cable anywhere near it. .... Why? because it induces so much noise that the data needs to re-transmitted over ad over again. it has has the apparent effect of slowing down the connection. This is particularly bad with Paradox alarms.

Some installers have no idea about this. One of the problems is that even if the cable is tested for transmission speed with the best of gear they do that before the alarm system is commissioned and the interference doesn't show.

This
Alarm system cables are notorious for spraying RF interference around.
I don't know why and I don't know why they don't use better gear and/or better cables, but "it's always been this way". Sigh

How much does shielded cable help with this? I have been using shielded cat6a where there is a emtal wrapped that goes around all the pairs as one cluster.

Speedtest 2019-10-14

cyril7

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#2348862 6-Nov-2019 09:59

Hi, shielded cables will assist with EMI related issues as mdooher describes, that said I have not seen such issues with Arrowhead alarm panels and this includes testing after both network and alarm systems are commisioned. I also note appropritate filter components on all the loop circuits of the Arrowhead circuit boards including the data channel to the control panel etc.

The downside of sheilded cables is managing earth loops, ideally they should only be earthed at the patch panel, if you also earth at the outlet or terminating equipment you can create more issues than you set out to fix.

We use STP cables at work exclusively for all data circuits above unclassified, but this is for security not interference purposes although that is an added bonus, however earth management is a thing.

Cyril

mdooher

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#2348873 6-Nov-2019 10:31

cyril7:

The downside of shielded cables is managing earth loops, ideally they should only be earthed at the patch panel, if you also earth at the outlet or terminating equipment you can create more issues than you set out to fix.

Cyril

Yep agree, If I have external interference on just a couple of runs I just replace it with fiber.

Matthew

neb

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#2348994 6-Nov-2019 13:52

mdooher:
Yep agree, If I have external interference on just a couple of runs I just replace it with fiber.

Another good reason to use fibre is to isolate equipment in high-risk areas, e.g. gear sitting outside the house from your internal network. I'm currently using a USB-powered WiFi bridge for that purpose, but during the rebuild I may replace it with fibre if I can find something relatively cheap. The TP-Link MC220 is about the cheapest I know of locally, and runs off 5V so I can power it from a UBEC at the end of a 12V line, if I can cannibalise some SFP's from somewhere. Or take a gamble on one of the infinite number of much cheaper Chinese ones, since I'm using it for isolation rather than long-distance high-speed data transfer it doesn't really matter if it's not quite up to spec.

old3eyes

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#2348997 6-Nov-2019 13:54

neb:
AKT:

2. Should I buy a reel of cable and then get Ethernet boxes at either end, or buy a readymade cable with RJ45 connectors?

Unless you're going to use the entire 100m or whatever's on the reel, it's always cheaper to buy terminated cable and cut the connectors off.

Thanx. I was wondering about doing that..

Regards,

Old3eyes

richms

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#2349118 6-Nov-2019 21:49

neb:
mdooher:

Yep agree, If I have external interference on just a couple of runs I just replace it with fiber.

Another good reason to use fibre is to isolate equipment in high-risk areas, e.g. gear sitting outside the house from your internal network. I'm currently using a USB-powered WiFi bridge for that purpose, but during the rebuild I may replace it with fibre if I can find something relatively cheap. The TP-Link MC220 is about the cheapest I know of locally, and runs off 5V so I can power it from a UBEC at the end of a 12V line, if I can cannibalise some SFP's from somewhere. Or take a gamble on one of the infinite number of much cheaper Chinese ones, since I'm using it for isolation rather than long-distance high-speed data transfer it doesn't really matter if it's not quite up to spec.

you can get loads of 100 megabit converters for dirt cheap from some of the IT recycler places. They dont seem to list them on trademe because the typical person would have no use and listing limits mean its better to list things that sell. I think I paid $30 for a pair of 100 meg ones with the older bigger gbic thing in them (what were they called) including wallwarts.

Richard rich.ms

neb

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#2349143 7-Nov-2019 00:36

richms:
you can get loads of 100 megabit converters for dirt cheap from some of the IT recycler places. They dont seem to list them on trademe because the typical person would have no use and listing limits mean its better to list things that sell. I think I paid $30 for a pair of 100 meg ones with the older bigger gbic thing in them (what were they called) including wallwarts.

Where did you get them? What's the connector on the GBIC? What are the power requirements?

Reason for asking is that if they require some oddball fibre connectors they may end up negating the cost of the converter, and if I can run it off 5V via a UBEC it'd be convenient since the only other thing I have is < 12V at the end of a run of cable.

cyril7

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#2349149 7-Nov-2019 06:37

Hi I take it you mean SC connectors as opposed to LC that would be found on an SFP transciever?, well if it is SC connectors built into the media converter then SC-LC patch leads are same/similar price to LC-LC.

Cyril

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