Connecting 2 networks 250m apart

fetster

fetster

fetster

Associate
Joined
20 May 2004
Posts
138
Hi, I need to connect 2 sites together which are 250m apart onto the same network. There is a lot of underground conduits which I can run cable through and also a low power electricity cabinet approximately in the middle of the run (125m distance) where I could boost the signals. I was just thinking of installing a network switch there plugged into the mains to boost the signals, providing 125m runs were not a problem.

What is the absolute maximum for ethernet cables?

Can anybody suggest an alternative solution (not too expensive). I can't really go down the wireless route as there are buildings in between the 2 sites and our radios that we have down there are struggling with range.

Thanks
 
I think you'll be ok with 125m runs, if you are lucky you may still manage to obtain 1Gbit, if not 100Mbit should not be an issue.

If you really need to be sure of 1Gbit+ then you will need to opt for fibre which will be £££.
 
You could do it with Cat5e, 125m shouldn't be a problem.

But bear in mind if the duct is 125m then you will need a 135m or so cable, for coming up into the buildings and routing etc all dependant on the layout of course, this could then mean 1GBit and above could become problematic.
 
You can get pre-terminated fibre 50/125 (MultiMode) for approx £250 for 300 Meters.

Whilst the run is possible using Cat5e which the standards say maximum length run is 100M, but I have seen runs of 130M work (I have also seen runs of >100M <130M that had major errors as well!!), I would recommend Fibre even though the initial outlay may be more expensive, it will be beneficial in the longer run, also if you made sure the fibre was OM3 or OM4 (For MultiMode) you could then run this at 10G over that distance as well although this fibre will be much more expensive.

Also what types of cables run in the conduits at the moment? IF there is power running in there then the only option to be certain of things working correctly will be fibre, as running any copper cable next to power will cause issues, especially over a long run.

Syngress
 
Do you really want to interconnect these buildings using cables that aren't actually rated good enough for the job? If it's going in for a business / enterprise, is ludicrous to be even thinking about copper for this.

Start looking for the kit to put a multichannel fibre connection in.
 
Get a pre-terminated fibre of the right length plus a couple of media converters/GBICs, you could even get 100meg media converters initially to save some cash.
 
+1 for fibre, agree with all the points raised above. I've had Cat5e runs of 120m with no probs...and ones of 30m with all sorts of errors because they run close to powerlines i didn't realise were there
 
Thanks guys. I think I will explore the fibre option, I thought it was going to be much more expensive than that.

If I was to go for pre-terminated fibre, what equipment would I need at either end to connect it to 1Gbit ethernet switches?

Finally, what would max length be for this type of fibre? (Considering linking another building approx 400m away with no options for boosters - Although I'll probably not need anywhere near that)
 
Do the switches have SFP ports or any other way to expand them?

If not, you can get media converters to turn the signal back into something meaningful for your current network.

Iirc, multi-mode fibre can do 500m with ease. So you should be fine.
 
What speed does it need to support?

OM3 will do 1Gbit at 1.5km, lower the distance and you increase the speed, it'll do 32Gbit at 250m for example.
 
Hi Guys, sorry to drag this up again. We are going to go down the fibre option. We maw have 2 separate buildings to connect to the main office. Fist one is approx 280m away and 2nd is 350m away.

I've looked at different types of fibre and I'm lost as to what type I need, what end connectors I need and how many cores I need.

I don't need anything fancy, each end of the network only has 1Gb switches with P2P network. Although if I'm going to the expense of paying people to run the cable then I want it to be future proof for at least 5 years or so.
 
iv done 160m run with cat6 and get full gigabit speed.

remember cat 6 is thicker guage than cat5 so you get less voltage drop over it.
 
Cyber-Mav said:
iv done 160m run with cat6 and get full gigabit speed.

remember cat 6 is thicker guage than cat5 so you get less voltage drop over it.
Click to expand...

The gauge of the actual pairs are not (necessarily) thicker. I've seen both CAT5e and CAT6 in 24AWG, although yes, CAT6 does also come in 23AWG from some manufacturers. The actual spec of CAT6 allows for the use of anywhere between 22 and 24AWG.

The main difference is the thickness of insulation.
 
You would want some switches with fibre gbit link ports, we generally stick to either cisco managed switches with gbit fibre gbics or the cisco linksys (badged as Cisco but actually linksys) with the same gbic links
 
make sure you get some sort of ruggedised fibre for pulling through, with a central strength member. Loose tube probably with a pulling eye on the end. You can't just pull a patch lead through 120m of duct :D
 
Wouldn't be a perfect solution, but if you wanted to would powerline adapters work for this? Could you even run in it's own Twin and earth cable as it's own sort of dedicated line?
But yeah don't do this, I'm just wondering :)
 
You must log in or register to reply here.
Back
Top Bottom