900mbit Speed Drop

[#1]

HI there, I am a new customer. I moved into a  new-build apartment a couple of years ago that had BT fibre built into the premises (with an ethernet network built in within the walls.) Unfortunately, when I moved in, I think that BT weren't offering fibre or Virgin were cheaper. I have been using Virgin 125mbit for the 2 years since then. But my contract ran out and they began charging me a silly amount for the internet so I looked around for deals and signed up to Plusnet 900mbit fibre.

The BT engineer came out and found that I already had everything in place and so no drilling etc was required by him. After the install was complete, I was using wifi to begin with and was getting speeds of about 400mbit when using speedtest.net/ . I didn't think anything of it and just thought that I could get better using the hardwired ethernet network in my apartment. Sure enough, at about 3pm, I got the ethernet network to work. I ran a speed test using speedtest.net/ and I was getting 922mbit/s. Suffice to say, I was over the moon with this result. These speed recordings occurred for a few hours but when the evening came my speeds have dropped to ~100mbit. I understand that the standard convention here is to use the BT speedtester and I get exactly the same results when I run a speed test using that. Originally, I just thought that maybe the network was overloaded in the evening or something, but ever since then the maximum speed I have been able to achieve over ether net is around 100mbit. Do you have any ideas what the cause of this could be or how to resolve it?

Thanks a lot,

-Leo

[#2]

but ever since then the maximum speed I have been able to achieve over ether net is around 100mbit. Do you have any ideas what the cause of this could be or how to resolve it?

@LeoX That sounds supiciously like you've got a cable in the connection thats only capable of 100Mb i.e cat5 . Check that all your cables are cat5e or better and have all 8 cores wired. It could also be a faulty cable, losing one of the cores will often allow the cable to continue to operate but only at 100Mb!

[#3]

Thanks for your reply. I will check that they are all cat6 or not, but that wouldn't explain how I managed to achieve 900mbit in the first instance though I don't think.

I( forgot to mention in my original post that I have rebooted my router several times to try to rememdy it. Actually, I just had a thought that I also connected my NAS to the router shortly afterwards. I see no reason why this woudl affect the speeds, but would it be possible?

Thanks again,

-Leeo

[#4]

@LeoX  Welcome to the Plusnet Community forums.

A drop to 100Mbps is indicative of a problem with your Ethernet wiring. You can check this by simply connecting a computer directly to your hub with the hub again directly connected to the fibre ONT.

By way of explanation, Fast Ethernet needs all 8 cores in the Ethernet cable, 100Mbps Ethernet only uses 4. If there is a break in one of the cores that is not used for the faster speed then it automatically reverts to 100Mbps.

Edit.

I’m a slow typist on a tablet,

[#5]

@LeoX

"Actually, I just had a thought that I also connected my NAS to the router shortly afterwards. I see no reason why this woudl affect the speeds, but would it be possible?"

Yes, it definitely could affect your speed test results.

If I am using my NAS to download a large file at high speed from the internet it seems to get "priority" over other devices connected to the router. My desktop PC slows down loading web pages and the Smart TV streaming often drops to a lower quality stream. If I force stop the relevant app on the NAS then everything returns to normal, though not always immediately.

[#6]

My NAS just hsits there ready to upload if I want files elsewhere. I'm off to Screwfix to pick up some cat 6 cables. You were correct. I have a lot of Cat 5, but only 2 Cat 6 haha. I need to get with the times!

[#7]

@LeoX cat5e will be fine

[#8]

I have cat6 cables now, but it is still about 90mbit on the tests unfortunately Any other ideas?

[#9]

@LeoX 

I find that one of these is a very useful tool. https://www.amazon.co.uk/dp/B09ZPT672H?pd_rd_i=B09ZPT672H&pf_rd_p=6806b386-5815-48a6-83af-c8f936535f...

[#10]

@LeoX 

"Any other ideas?"

Have you tried disconnecting or switching off every device connected to your router, both wired and wireless, except for the cable connected PC that you are running the speed test on, and doing another test?

[#11]

I just unplugged my NAS and the same result unfortunately. That is the only other device that was connected.

[#12]

Thanks for the suggestion, but it seems a bit overkill for me seeing as I don't reallyt work in networking and just want to get the internet speed that I pay for!

Weirdly enough, over wifi, I can get about 352mbps. It might be the cabling withing the walls of my home that is not up to the task? This is frustrating.

[#13]

@LeoX 

It would tell you if it was your property cabling. You don’t need to work in networking to use this cheap tool. You simply use patch cables (if checking between two sockets) to connect it to the two ends of the property cable and watch the flashing lights. 

[#14]

It wasn'ta  case of operating it. I'm an engineer that works in science, so I would hope that I would be able to figure it out!I meant for the number of times that I would potentially use it, but I will place an order if you think that it is necessary. It's my birthday today, so I'm a bit busy with family etc, so apologies for my sluggish responses.

[#15]

You could probably carefully remove one of the faceplates and see how many cores the cable has. If its only 4 then you are never going to get above 100Mb without a rewire. If its got all 8 cores, then the tester would be useful to check for faults and you may be able to fix them. You may need a punch tool to re-seat the cables