Home Network Issue

Shimrod · March 14, 2025

Hi, newbie here (in the UK), have been watching Linus's YT for a few years now, but decided to join the forum and ask if someone can help me with an issue...

Recently been trying to setup a small home network. The Internet i have has a box on the inside wall installed by my ISP (Plusnet) into which the input signal fibre optic glass cable comes in. The box also features an ethernet port to connect to my ISP router and a DC power jack as it needs power. Due to the placement of the box on one side of a door and all my pc stuff being on the other side, i have run some trunking around the door frame terminating in a 4 port RJ45 wall box i bought (Rhinocables); my intention was to connect the cable from the ISP box to the first port and use a short patch cable to connect it to the WAN port on my ISP router; the first LAN port is connected to my PC via a Cat7 Patch cable and the other LAN ports on the ISP Router will be patched into the other ports on the wall box and from the box have hard wiring running to other parts of the house in the future.

My first issue was the cable i had running through the trunking was a CAT6a cable, and the ports on the wall box were Cat6. The cable had standard RJ45 plugs on the ends; i cut the connector off the end that was going to be wired to the first wall box port, but I had trouble making all 8 connections with the punchdown tool i bought, but eventually i did it, using a tester to confirm all the lines were connected and my computer is fine and has internet access. However, doing a recent online speed test i discovered my 500 mb/s line was only getting a download speed of about 90 mb/s, with an upload speed of 70 mb/s. When i ran a cat6 cable directly from the ISP wall box to my ISP router and re did the speed test it jumped to just over 500 mb/s (but curiously the upload speed remained the same). So what i can't fathom is why the drop in speed when using the port i've wired up. The patch lead from the port to the WAN port was a Cat7 and only about 20" long, The Cat6a cable from the ISP box to my port is about 30ft, but the Cat6 i used to make the direct connection was nearer 33ft.

Any ideas anyone?

Donut417 · March 14, 2025

24 minutes ago, Shimrod said:

Any ideas anyone?

Because the speed was below 100 Mbps it means that it's a cabling issue. You only need 4 working wires for 100 Mbps and below, but need all 8 wires for anything faster than 100 Mbps. Maybe try reterminating the cable.

25 minutes ago, Shimrod said:

Cat7 and only about 20" long, The Cat6a cable from the ISP box to my port is about 30ft, but the Cat6 i used to make the direct connection was nearer 33ft.

Ethernet is good up to 100 meters.

Shimrod · March 14, 2025

44 minutes ago, Donut417 said:

Because the speed was below 100 Mbps it means that it's a cabling issue. You only need 4 working wires for 100 Mbps and below, but need all 8 wires for anything faster than 100 Mbps. Maybe try reterminating the cable.

Yes, that seems to be the issue, even though the tester showed 8 pins connected before i manoeuvred it into the wall socket, testing it again using the patch cable just now shows one pin is now disconnected, just my luck it wasnt one that would have broken the link completely so i would have known straight away.

Think i may ditch the Cat6a cable and buy some unterminated Cat6, and put a male connector on the other end for the ISP box. As i said the Cat6a took a few attempts to play ball with the jack when i first attempted to wire it up, i think the wires or the insulation in the Cat6a are perhaps too thick/thin or something. Thanks for the info!