[Closed] Network Gurus 2 - how many cables?

It depends where the bottleneck is. You can only have 1 cable connected to the switch from the router. If all your stuff needs that signal from the router then there is no point having 2 cables running between a switch by the router and the switch in the outhouse.

Is it even possible to run more than one network cable to the switch, and will that increase its bandwidth, or is every device connected to it just going to have to share a single cable back to the router in the house?

You'd need an expensive switch, at each end, which supported channel bonding of interfaces.

In a cheap one spanning tree will detect dual paths and shut one port down to prevent a broadcast storm loop.

So, no advantage - unless you want physically separate LANs or are going to use the other cable for a phone (old style Pots rather than VoIP).

Every device in the garage will share the single cable unless you get serious/expensive. Do you really think you'll fill up a gigabit connection with a few devices in the garage?

Just use 1 cable, if it's gigabit for normal use that's a lot of bandwidth.

BUT - if running the cable involves any work like burying, trunking, sealing it in or anything like that run at least 2 cables at the same time. It's not any more work, and if it gets damaged you don't have to rip it all out and do it again, you just switch to the other cable. Anyone that has done more than a few cable runs will tell you to do this - they'll either have had moments they wished they'd done it, or were glad they had!

Do you really think you’ll fill up a gigabit connection with a few devices in the garage?

@morphio yeah was literally just thinking that as you were replying. Makes sense.

Yes one cable to your Poe switch and cable the other devices in your garage LAN back to it. Might be worth putting two cables in just for redundancy in case one fails or eaten by a rodent 😃
Of course if you do run two cables so you could use them both to feed two separate Poe switches for instance.
I'd run two just in case, even if you don't use/need the other.

If you can and the run isn't too tricky, run cat6 cable. Gigabit should be plenty of bandwidth, but you'd always have the option of running something faster like 2.5 or 10GbE over it in future if needed. I doubt you ever will, but the price of the cable isn't much different, just a bit stiffer than cat5e and doesn't go round quite as tight corners.

Is it worth getting shielded if running a couple in a trench next to a power cable, or will bog standard external be ok?

I suspect cat6 would probably be fine, I've often seen it alongside power cable without issues, but I'm not expert enough to say for sure, so I'll defer to someone else.

How close to the power cable and for what distance? I assume if buried underground you're either running it in some pipe or using armoured cable?

or is what I actually want to do, not have a separate POE router in the garage, but a patch panel instead, and run everything back on its own cable to a single POE router in the house ? Or is that massive overkill?

How far away is the garage? ISTR there's a maximum length with POE.

If it's not a massive pita, then more cables and a patch panel is by far the most flexible solution - but I'd be surprised if you really needed more than gigabit.

The power cable is armoured yes. It’s running in a shallow trench, so the various cables are probably going to be touching. Don’t want to use conduit if I can get away with not, was just going to sling some gravel on top! About 35m.

Run it in a cheap hose pipe

ISTR there’s a maximum length with POE.

There's a max length for 100 Base-T and 1000 Base-T.

PoE just degrades slowly as the resistive losses in the conductors take up more volts over a longer run.

I’ve often seen it alongside power cable without issues, but I’m not expert enough to say for sure, so I’ll defer to someone else.

Fine, esp if the power cable is armoured.

The risk is, someone cuts through the power cable with a digger / saw etc and for some reason it doesn't trip the RCD or fuse but connects the power conductor to a CAT-5 conductor, this making the CAT-5 live, which Ethernet kit isn't designed to handle, so potentially giving someone a shock. More likely there'd be a quiet pop and an interface would blow on the switch.

It's unlikely event combined with unlikely event, so getting pretty theoretical......

EDIT: Although I'm sure someone will be along soon to say 'you're all going to die'.....

Don’t want to use conduit if I can get away with not, was just going to sling some gravel on top!

I would put the cable(s) in plastic pipe and include a draw wire for when you need to pull a new one through.

Am I just overthinking this?!

Yes.

I'd give a fuller answer but I'm time-poor for a few days. The short answer is, run a CAT5e cable from point to point, and I'll cheerfully fight anyone who disagrees with me because they're wrong.

I would put the cable(s) in plastic pipe and include a draw wire for when you need to pull a new one through.

Also, that.

Agree with Cougar....but is it worth future proofing by it running a couple of cat 6 cables? Will only cost £45 or £50.

No.

Slightly longer answer.

There is no point running CAT6 unless you're getting a Structured Cabling Engineer to install it or you plan to do so in the future (or you know what you're doing sufficiently to be not asking this question in the first place). It's more expensive, it's awful stuff to work with and it gains you the square root of geoff all.

Your "future proofing" would be as slowoldman said, leave yourself the ability to pull new cable as required. By the time you need CAT6a, CAT37 will be the standard assuming cables haven't been completely obsolesced by wireless technology by then.

And if you're driving POE devices then that's 10/100 by definition, they're mutually exclusive. It's like drinking shots out of a half pint mug and wondering whether you'd be better off upgrading to a 2L stein instead of a pint glass.

If you don't want to run lots of cable a pair of these will give you 1.7Gbs throughput.

https://eu.store.ui.com/collections/unifi-network-routing-switching/products/unifi-building-to-building-bridge

I wouldn't run your network cable right alongside the power. Trench to whatever depth you think is appropriate for the armoured power cable plus a bit extra (2 spade depths?). Sand in trench, power cable, more sand, backfill trench halfway and bury some electric warning tape, then drop in your network cable in some sort of protection/sand, and then I'd lay some more electric warning tape directly under the turf. This gives you some separation without without having to do extra digging.

Agree Cat6 is pointless for this but...

And if you’re driving POE devices then that’s 10/100 by definition, they’re mutually exclusive.

Eh? PoE supports 1Gbps - or did you just miss off zeros?

This site might help put in perspective how much of the 1Gb link the cctv would use.

https://www.cctvcalculator.net/en/calculations/bandwidth-calculator/

8x4K is ~70Mb/s

I'd disagree - I'd pull 2 cables through before you bury the pipe, and yes leave the string in there.
Pulling cable through some straight PVC pipe or conduit is trivially easy, even with cat6 before you bury it. Once you bury it and put kinks in getting it down and up it gets a lot harder. Handy hint to get the pullstring in to begin with - tie a plastic bag to the string and use a hoover on the other end to suck it through. Magic.

And if you’re driving POE devices then that’s 10/100 by definition, they’re mutually exclusive.

Definitely not. You can get 2.5 and maybe even 10 GbE. I've only ever touched 1 GbE myself though.

I wouldn’t run your network cable right alongside the power.

Theoretically, you shouldn't.

Practically, it'll likely make bog all difference. If you're that worried, lay STP.

Eh? PoE supports 1Gbps – or did you just miss off zeros?

Definitely not. You can get 2.5 and maybe even 10 GbE. I’ve only ever touched 1 GbE myself though.

Happy to concede I'm wrong on this point but, how's that work then?

10/100 uses four of the eight wires. POE uses another pair to transmit power. Gigabit Ethernet uses all eight. If you can get gigabit POE, that's something I've never come across.

I just ran my CAT-5 along the fence....

[url= https://live.staticflickr.com/8645/15968927105_72a7f63789.jp g" target="_blank">https://live.staticflickr.com/8645/15968927105_72a7f63789.jp g"/> [/img][/url][url= https://flic.kr/p/qk7VFp ]Dual CAT-5 running along fence[/url] by [url= https://www.flickr.com/photos/brf/ ]Ben Freeman[/url], on Flickr

10/100 uses four of the eight wires. POE uses another pair to transmit power. Gigabit Ethernet uses all eight. If you can get gigabit POE, that’s something I’ve never come across.

The PoE and the data can share the same cores, they don't interfere.....

With CAT-5 the data is taken differentially between each pair, so as long as each pair has the same PoE voltage (+48v or 0v) it doesn't have any effect on the signal.

NB There are so many PoE standards and non-standard implementations, that loads of different permutations are in use. Our radio products used PoE long before there was a standard and we just stuck 48v DC on 4 cores and used the other 4 for ground.

I wouldn’t run your network cable right alongside the power.

With BT phone cables, which use straight cores, you will get some small 50Hz pickup from the mains to the data cable.

CAT-5 is twisted pair, which is (virtually) immune to induced currents as the angle of each wire is continually changing, so the phase of the induced current continually changes, cancelling itself out over each full rotation. Obviously, not every rotation is completely symmetric and you won't get a full integer number of rotations throughout a given length, so you still get a miniscule induced voltage (several orders of magnitude down), but you'd struggle to measure it and it has no effect on the data.

This site might help put in perspective how much of the 1Gb link the cctv would use.

https://www.cctvcalculator.net/en/calculations/bandwidth-calculator/

8x4K is ~70Mb/s

that's a handy link, thanks! Possibly up to 4x that dependent on quality settings, but yeah well under 1Gbp/s

thanks for the help all! 😃