Office is 420m away from the landline relay box, need help figuring out a solution

Question

We are an agricultural technology startup, we develop and provide advanced solutions like hydroponics etc. We are based in Egypt, Africa; where the most you can wish for is FTTC, regardless, the neighborhood we are in won't be getting FTTC until the end of the year. We have VDSL over copper wires.

The issue I am facing atm is that the office is on an 8.5 acre land, the telephone relay box is at the front gate and the office building is approximately 420 meters away from the box, connected above ground via a single UTP copper wire. As a result, the signal quality deteriorates significantly by the time it reaches the router/modem. Here are some numbers that I picked up a couple of days ago through the current router provided by the ISP.

At the box: Noise Margin (Up/Down) : 5.1/10.5 dB
Line Attenuation (Up/Down) : 17/37.5 dB
Output Power (Up/Down): 6.1/13.2 dB

At the office:
Noise Margin (Up/Down) : 5/5.9 dB
Line Attenuation (Up/Down) : 16.4/42.7 dB
Output Power (Up/Down): 6.2/14.4 dB

So, one solution I thought of is to get a decent new router and place it near the front gate, connect a media converter through a gigabit LAN port with cat6 and use an underground shielded fiber optics cable to reach an unmanaged switch at the office.

Another solution that an acquaintance recommended is to install two managed switches, one near the front gate and the other at the office, connected through two underground shielded cat6 cables and create a trunk I believe?

I am not sure if these are good solutions or if there are better routes to go. I am not a networks professional, I just have some little knowledge and we don't have a specialized IT personnel. We are looking for connection stability most of all for at most a 100 users, currently 60.

TL;DR: UTP telephone copper wire extends over 400 meters to reach the router (office), internet stability is horrible and unusable, need help figuring out how to fix the issue.

Answer 1

400 meters is well beyond the range of UTP Ethernet cable, so it should not be used. Fiber optic cable (single mode) is a very good option, albeit more expensive. Note that fiber does not need to be shielded as it is impervious to electrical noise.

If you go with this option, be sure you follow local regulations (if any) regarding the proper installation of underground cable.

Answer 2

I would definitly go with Ron's solution. You don't need a trunk, beside it would be for a different problem setting. On either side you would put a switch and connect them with two cables and connect them via lacp(~trunk as your friend suggested). But that would not speed up anything or get rid of some of your problems.

I think you should try it as you said. Put a media converter and set a single mode fiber optic cable to your office. If you put a multi mode cable, it would not suffice your needs. Multi mode has reaches 550 meter in laboratory situations.

One of the problems you could face, beside putting the cable really to the ground, could be heat issues. As GBICs get warm they tend to stop working.

Watch out, it can get really expensive with gbics, fiber optic cables and media converters. Good luck.