Ethernet cable length

Does anyone know if running an ethernet cable about 80m would still provide decent signal strength/speed?
I am trying to get wifi into an outbuilding from the main house.
I'd be grateful for any thoughts or suggestions.

Thanks.

The cable can be up to 100 metres.

It's technically a bit more complicated than that. Technically the standard says something like 90m allowing for patch leads either end, so you can squeeze a bit more if you go for a single length (port to port with plugs each end) as you dont have the losses of two sockets.

However if they are out buildings you need to consider the possibility of different earth potentials at each end which can cause problems for copper based ethernet. Personally I would be strongly tempted to run some fibre optic cable myself. You can get preterminated SWA fibre patch cables, and being electrically isolated you side step a range of issues. That said you could use PoE to power an access point at the other end and side step the ground issue.

In reply to a post by jabuzzard:

Personally I would be strongly tempted to run some fibre optic cable myself. You can get preterminated SWA fibrepatch cables, and being electrically isolated you side step a range of issues. That said you could use PoE to power an access point at the other end and side step the ground issue.

Seconded, fibre to ethernet convertors can run from 5v USB ports (or phone power chargers!), or PoE. Solves the electrical problems outside.

I'm considered running fibre cable between two switches in two buildings (duct exist between them so don't need SWA) but when trying to search for the fibre cable things seem more complexed than just choosing between single or multi mode fibre (e.g OM1,OM2 etc). Have you got any recommendations or guidance. How hard is it to fit connectors on the ends?

In reply to a post by dect:

I'm considered running fibre cable between two switches in two buildings (duct exist between them so don't need SWA) but when trying to search for the fibre cable things seem more complexed than just choosing between single or multi mode fibre (e.g OM1,OM2 etc). Have you got any recommendations or guidance. How hard is it to fit connectors on the ends?

To be honest it would be easier and cheaper to use Ethernet cable or point to point wifi

As you only have 80 meters that would be perfectly fine for point to point wifi as it's designed to go a lot further distances than you require and would still cost far less than running fibre.

In reply to a post by robertcrowther:

To be honest it would be easier and cheaper to use Ethernet cable or point to point wifi

As you only have 80 meters that would be perfectly fine for point to point wifi as it's designed to go a lot further distances than you require and would still cost far less than running fibre.

Hi Robert, I think your replied should have been to the OP not me.

Distances won't let me use ethernet and obstructions in the way wont let me use point to point wifi so for me fibre is really the only option that's why I asked about what type of fibre to use.

Depends entirely on the length of the run. If it is more than a couple hundred metres I would be strongly tempted to go single mode. In fact given the very small price differential between single mode and multimode optics for both 1Gb and 10Gb I would be tempted to go single mode anyway. The cable price is basically the same.

As you have discovered with multimode fibre there are lots of different standards, and basically every time some new speed comes along they introduce a new standard. So if you fitted OM1 for 100Mbps, you need to upgrade to OM2 for 1Gbps, and then OM3 for 10Gbps and OM4 for higher speeds. Long term using multimode for fixed/structured fibre cable can be a mugs game as long term it would have been cheaper just to fit single mode first time around. That said a pair of OM3 today and you are good for 10Gbps at 300m and 40Gb at 240m.

Despite using fibre extensively at work now for over 15 years I have never terminated the stuff, always getting an outside firm to do it or buying pre terminated fibre. A quick check on eBay shows you can get a cheap cleaving kit for under £30, and some more Googling showed Fujikura Field OM3 LC connectors are ~£8 each, you will need four connectors for a standard link. I would be tempted to find a local firm that will let you run the cable yourself and do the termination.

Thanks for the advice, it was very helpful

Basically, I was hoping that I could just get away with plugging one end of the Cat7 cable into the existing main router and then the other end into a bridged router 80m distant in the outbuilding.

Possible?

Possible yes.

In reply to a post by lodge:

Basically, I was hoping that I could just get away with plugging one end of the Cat7 cable into the existing main router and then the other end into a bridged router 80m distant in the outbuilding.

Possible?

I believe the first post from jabuzzard gave you the answer to that question and also one of the risks of running ethernet between buildings.

Edited by deleted (Wed 13-Nov-19 09:39:30)

Unfortunately the thread rather became hijacked by others expounding their own projects, so the answer to my original post was not clear from all the unrelated posts.

But thank you for your interest, anyway.

In reply to a post by lodge:

Unfortunately the thread rather became hijacked by others expounding their own projects, so the answer to my original post was not clear from all the unrelated posts.

The answer to your question was clearly given long before I hijacked the thread.

The recommendation by those responding to you said it was possible although suggested a fibre cable would be a better option, my question simply expanded on that point and should have been helpful to both of us. I am sorry if you felt it wasn't and sorry for hijacking your thread.

Don't use Cat7 cable for anything. It is not certified for transmitting ethernet of any description over any distance, and unless you use the specialist connectors (which you wont be) you will make things worse by going from balanced pairs to in effect miniature coax which will be not corretly terminated unless you have those specialist connectors.

Nobody should use anything above Cat6a unless you are doing 40gbps ethernet in a data centre with patch leads (no structured wiring) under 30m then you could in theory use Cat8, but there are currently no products on the market and direct attach and active optic cables are likely much cheaper for many years to come.

In reply to a post by jabuzzard:

Don't use Cat7 cable for anything. It is not certified for transmitting ethernet of any description over any distance

Are you sure of this? Not even under ISO 11801? You might want to check on that

That is not an IEEE 802 ethernet standard and as such my statement stands, Cat7 is not certified for carrying Ethernet of any description by the IEEE Ethernet standards. The ISO can write random standards to their hearts are content, but it is the IEEE standards that govern ethernet. Put another way it was written in the expectaion that the IEEE would use Cat7 for higher ethernet speeds, then they didnt.

Anyone using anything higher than Cat6a is a gulable fool who is actually making things worse because they will not be using the specialist connectors that the higher standard requires.

https://se.rs-online.com/web/generalDisplay.html?id=...

I think you may be getting mixed up between 7 and 7a

Also check out iee802's website as it does show that cat7 is certified