1.5Gbps Internet Plan but only getting 800Mbps after fiber line change

[hys17]

Not sure if the internet question belongs in this forum. Apologies if I've mistaken.

This might be the weirdest network thing I've ever encountered and I could really use some insights. Hear me out if you can.

I've been with this ISP for almost 2 years, under fiber internet plan 1.5Gbps. They are a subcontractor of Bell Canada.
They use a Nokia ONT to an Eero modem/router. I then quickly switched the Eero to my Asus RT-BE96U router to have more flexibility and features for my home network. It's been working pretty solidly, with download/upload speed between 1.3-1.5Gbps.

3 months ago, there was an internet outage. The ISP sent a Bell technician and found there was a line cut near a neighbor's house. Instead of pulling a new line, the technician used (I guess) a backup line within the same fiber cable (don't know the technical details).

The backup line tested fine, and initially I was only getting 30-50Mbps. After calling their management team, they upped the line speed to 1.7Gbps.

Then the speed testing changed to 800Mbps download and 1000Mbps upload.

I should elaborate that the speed testing has always been conducted on the Asus Merlin firmware webUI, at Adaptive QoS - Internet Speed page (powerd by Speedtest.net I think). Both before and after the outage, if that makes it consistent.
(I did try speedtest.net on a wired PC and the speed is always lower for some reason, with 2.5Gbps lan speed.)

Then I tried many calls with the ISP and the ISP confirmed many times with Bell that they are seeing everything shows normal on their end. So it's got to be my equipment.

I even tried to switch back to the Eero for further troubleshooting but for some reason, it just doesn't connect anymore.

Now Bell Canada refuse to send another technician to take a look at the line because nothing is wrong on their end, and my ISP doesn't own those lines so they can't physically do anything about it...

This doesn't make sense to me at all, as I understand and agreed with the Bell technical support, a fiber line is either no speed or full speed (especially if they confirmed multiple times about the speed profile on their end). But the only logical explanation at this point, is the "backup" line that was switched to, since that's the ONLY thing that got changed since the outage.


Tl;dr: After an outage, the ISP switched the fiber line. Since then I couldn't get the speed I should be getting for my fiber plan. Everything else looks normal though.



QUESTION: Is it theoretically possible that a fiber line can be limited by some sort of physical reason (like loose/bad wiring/cabling), even if it electronically looks fine?
In this case, both Bell Canada and the ISP confirmed that they set up the line properly, and nothing has changed on my end either(swapped ethernet cables to troubleshoot but no change).

Anyone could share some insights are hugely appreciated!

 

[pricklypunter]

Make sure there are no tight bends on the fiber, either in the demarc or going to your ONT. Make sure the fiber ends (I'll assume APC SC type here) are not damaged and are really clean, check with a scope. Try running your wired speed test right from the ONT, same result?

 

[hys17]

Make sure there are no tight bends on the fiber, either in the demarc or going to your ONT. Make sure the fiber ends (I'll assume APC SC type here) are not damaged and are really clean, check with a scope. Try running your wired speed test right from the ONT, same result?

Ah thanks.
Not seeing any tight bends on the fiber cable, as it directly comes from the same wall of the external of the house and through a hole back to the internal side of the wall, then straight to the ONT.

How do I test the speed directly from the ONT though?
Judging by the ONT lights, it seems to be 10Gbps between the ONT and the Asus router (using the 10G WAN port). The ONT's data LED would show green for 1Gbps, yellow for 2.5Gbps and blue for 10Gbps. Currently, it's showing blue and the Asus router's webUI show's 10Gbps on the WAN port as well.

So strange...


Edit: grammar.

 

[Exhaust8890]

How do I test the speed directly from the ONT though?

Plug the computer directly into the ONT, bypassing the router.

 

[pricklypunter]

Those LED indicators just mean that the link has been established as either 1Gbps, 2.5Gbps or 10Gbps. As you have a 10Gbps port on the Router connected, the link is up at 10Gbps. Obviously, you'll only get whatever speed the the ONT has been provisioned for

To test from the ONT, connect a laptop or desktop, with an adapter capable of the expected speeds, directly to the port on the ONT that goes to your Router. reboot the ONT and let your endpoint grab an IP address. Then run your speed test again. I would also suggest that you use a clean live linux (can be run from a usb stick), download and install the linux speedtest script and do it that way. That will rule out any other fluff getting in the way

 

[hys17]

Those LED indicators just mean that the link has been established as either 1Gbps, 2.5Gbps or 10Gbps. As you have a 10Gbps port on the Router connected, the link is up at 10Gbps. Obviously, you'll only get whatever speed the the ONT has been provisioned for

To test from the ONT, connect a laptop or desktop, with an adapter capable of the expected speeds, directly to the port on the ONT that goes to your Router. reboot the ONT and let your endpoint grab an IP address. Then run your speed test again. I would also suggest that you use a clean live linux (can be run from a usb stick), download and install the linux speedtest script and do it that way. That will rule out any other fluff getting in the way

Thanks for the instructions.

I did manage to connect the ONT directly to my Windows 11 PC. Showing 10Gbps LAN speed.

My ISP has some weird PPPOE and VLAN setup which for some reason, I cannot successfully configure on the PC at the moment (getting connection error). Might have to do more digging on this (haven't done a dial-up connection on PC for almost 2 decades lol)...

Hypothetical question though: If the direct connection still shows 800Mbps/1000Mbps download/upload speed, what are the chances that the fiber line has some physical issues (if Bell Canada did set up the speed properly).

The whole time, what's most baffling to me, is the download speed is slower than the upload speed. Especially if the ISP has set the speed profile to 1.7Gbps, why the download speed is being "throttled" more?

 

[tgl]

Download speed different from upload speed is far from unusual. If your ISP swears that it's configured the same on their end, the first thing that comes to my mind is a buffering problem. There are certainly going to be points in your connection out to the wider internet where the line speed changes. When data is being transmitted in the faster-to-slower direction, the switch or router at the changeover spot has to deal with that somehow: either keep the data in a local buffer until it can be transmitted, or drop the data on the floor and expect the data source to retransmit later, or tell the source to slow down. The first answer does not work for speedtests, because the source is going to keep trying to transmit as fast as possible, so it will soon overwhelm whatever RAM the switch/router might have available. The second answer solves the problem locally but of course destroys your throughput, since the source will not retransmit right away. So the only answer that really works is "tell the source to slow down". That means you need flow control.

I am wondering first if your router's WAN port has flow control enabled, and second whether maybe this fallback fiber connection is missing flow control at one end or the other.

 

[pricklypunter]

Dirty connections or poor splices are your only real enemies here, as far as the physical stuff goes. There's a million other issues that can be at play in the software/ firmware GPON/ XGS-PON realm, that can cause all manner of headaches. I would have your ISP create a ticket with Bell to get the path verified, that way they can clean and scope every connection from the OLT right to your ONT

 

[alaricljs]

You keep running the same test... It's typically fine to do that, but when the test gives unexpected results consistently it's time to compare that to some new tests. Especially when everyone else insists the "pipes" are fine. fast.com is my go-to

 

[klui]

Confirm that your wired connection from your ONT and router hasn't changed.

If that's the case the only physical change was between your OLT and your ONT's splitter on the pole or in some cabinet. I think @pricklypunter's assessment is accurate. Go to your router and look at your WAN port's error counters. It'll be more useful if you have some sort of NMS to give you historical information.

Using your own equipment has many benefits but this situation will work against you. ISPs are not obligated if things "look good" on their end to help you with your own network. You need to work out an agreement with your ISP and temporary use their supported equipment until the problem is fixed. Using their equipment will force them to honor your subscription's support agreement. The eero not connecting in place of your Asus shouldn't happen. It's possible your eero account has been deactivated as you haven't used it for a while; your ISP might impose a limit on how many MAC addresses your ONT recognizes and you using your Asus and your computer went over the threshold so your eero couldn't connect.

If your OLT serves many heavy users it's not unusual you won't get full bandwidth from speedtests. Simply schedule a test every 30-60 minutes for a couple of days to see what you get. Use Speedtest.net's CLI.

 

[hys17]

Download speed different from upload speed is far from unusual. If your ISP swears that it's configured the same on their end, the first thing that comes to my mind is a buffering problem. There are certainly going to be points in your connection out to the wider internet where the line speed changes. When data is being transmitted in the faster-to-slower direction, the switch or router at the changeover spot has to deal with that somehow: either keep the data in a local buffer until it can be transmitted, or drop the data on the floor and expect the data source to retransmit later, or tell the source to slow down. The first answer does not work for speedtests, because the source is going to keep trying to transmit as fast as possible, so it will soon overwhelm whatever RAM the switch/router might have available. The second answer solves the problem locally but of course destroys your throughput, since the source will not retransmit right away. So the only answer that really works is "tell the source to slow down". That means you need flow control.

I am wondering first if your router's WAN port has flow control enabled, and second whether maybe this fallback fiber connection is missing flow control at one end or the other.

Interesting!

From what I can tell, the Asus router doesn't seem to have the WAN flow control enabled (google tells me that it's only enabled if there's dual WAN configuration, but in my case there is not).
Not sure how to check the fiber connection side though.

I've never thought of this aspect though. Thank you for the insight!

Edit: I'm aware that difference between download & upload speed in general, but it's usually the other way around (upload is slower) in my experience. Hence the puzzling for me.

 

[hys17]

Dirty connections or poor splices are your only real enemies here, as far as the physical stuff goes. There's a million other issues that can be at play in the software/ firmware GPON/ XGS-PON realm, that can cause all manner of headaches. I would have your ISP create a ticket with Bell to get the path verified, that way they can clean and scope every connection from the OLT right to your ONT

Confirm that your wired connection from your ONT and router hasn't changed.

If that's the case the only physical change was between your OLT and your ONT's splitter on the pole or in some cabinet. I think @pricklypunter's assessment is accurate. Go to your router and look at your WAN port's error counters. It'll be more useful if you have some sort of NMS to give you historical information.

Using your own equipment has many benefits but this situation will work against you. ISPs are not obligated if things "look good" on their end to help you with your own network. You need to work out an agreement with your ISP and temporary use their supported equipment until the problem is fixed. Using their equipment will force them to honor your subscription's support agreement. The eero not connecting in place of your Asus shouldn't happen. It's possible your eero account has been deactivated as you haven't used it for a while; your ISP might impose a limit on how many MAC addresses your ONT recognizes and you using your Asus and your computer went over the threshold so your eero couldn't connect.

If your OLT serves many heavy users it's not unusual you won't get full bandwidth from speedtests. Simply schedule a test every 30-60 minutes for a couple of days to see what you get. Use Speedtest.net's CLI.

Thank you both for this!

I can confirm nothing else has changed since the outage, outside of the fiber line.

And VMedia has created tickets with Bell in the past 3 months for further troubleshooting but Bell kept saying everything looks fine on their end.

I agree that in this case using my own router is working against me. So I'm looking to probably get a replacement Eero just for the troubleshooting purposes. What's funny is even the VMedia supervisor agreed that it probably has nothing to do with the Eero or my own gear, but rather a Bell fiber line issue (which is the most logical sense).

 

[hys17]

You keep running the same test... It's typically fine to do that, but when the test gives unexpected results consistently it's time to compare that to some new tests. Especially when everyone else insists the "pipes" are fine. fast.com is my go-to

Hmm just tried fast.com but on my wired PC the results are even slower ( around 600Mbps down & up). Maybe it's not widely implemented in Canada?

To add though, both Bell and VMedia recommended Speedtest.net for general testing. They are taking the results on my end, as long as it's through a direct wired connection. They just can't confirm the issue without using their own equipment I think.


By the way, Bell called today and finally decided to send a technician out and see what's going on. Hopefully tomorrow they'll locate the issue and perhaps pull a new line.

Fingers crossed and I'll report back then.

Thanks for all the help!

 

[RecursiveG]

If you can log into the ONT, it should have a RX laser power reading, which may give some clues about a bad fiber. If bent or dirty, power goes down. You may want to confirm with the technician when they come. Though I'm not sure how much that can affect the speed, if at all.

 

[pricklypunter]

If you can log into the ONT, it should have a RX laser power reading, which may give some clues about a bad fiber. If bent or dirty, power goes down. You may want to confirm with the technician when they come. Though I'm not sure how much that can affect the speed, if at all.

Being able to only see the light level reported by the ONT, is pretty much useless. Unless that is, you have a birth certificate for when the original path was verified, or happen to know the input power of the shortest wavelength being carried, what splitters it passes through enroute, how many splices are in it along that length and the actual fiber length, from the sfp module in the cab, otherwise you are comparing it to, what exactly? Bell can look at that remotely using their software tools and determine if within normal parameters, or closely matches their birth certificate, given network and link loss design etc.

I'll say that your light level, at the ONT, should be between around -12dBmW - 20dBmW, for straight data service, and quite a bit hotter, perhaps
-8dBmW - -4dBmW for an area that uses RFoG.

Dirty fiber connections are quite probably the most common issue whenever you see weird things happen with a fiber install. Closely followed by poor splices causing attenuation, reflection and data errors.

I'm quite sure if the tech they send is decently familiar with fiber, the issue will be resolved, and if not, there's always Rogers

 

[hys17]

First of all, I'd like to thank all of you who contributed to this thread.

The Bell technician came yesterday and I'd like to provide an update.

In short, the problem seems to be resolved for now, that I'm getting over 1500Mbps down (non-peak hours), 1000Mbps up.

------------------------------------

The technician did not replace the fiber line which was disappointing. Reason being that from their testing, the signal loss is within normal range (based on their standard, it needs to be higher than 4 (don't know the exact terminology), and in my case it's only 1.5). Therefore they cannot just pull a new line based on customer's request.

However, I did convince the technician to move the fiber line from the kitchen area to the basement, where all my networking gears sit (desktop PC, home server, etc.). So it's easier to troubleshooting (swapping cables and such), even though we both agreed that it probably wouldn't change anything.

After the location move, did more testing and it did not make any difference.

The technician then suggested to contact my ISP for further diagnostics, as everything looks fine on their end.


ISP contacted me that evening. Tried more troubleshooting with the Eero device and was able to get it connected this time. The Eero app showed my WAN speed is 1.6Gbps down and 1Gbps up.

The problem is the Eero Pro 6E only has 2 ethernet ports, 2.5Gbps and the other is 1Gbps. So we'd face an obvious dilemma, where either using 2.5Gbps for WAN to get the full 1.6Gbps, but cannot test the actual full speed using local LAN port (and the speed testing feature on the Eero app is no where near transparent as something like speedtest.net); or using 1Gbps for WAN and 2.5Gbps for LAN but still cannot testing the full WAN speed.

Interesting, while using the Eero, the speed testing on my PC via LAN, showing close to 1000Mbps down and 900Mbps up. So there's some progress.


So I switched back to my own router Asus RT-BE96U and the speed is back to 800Mbps down and 1000Mbps up.


I demonstrated the dilemma of using the Eero to the VMedia support agent and they discussed with the team (according to themselves), and came back and basically said to keep testing for a day or so and they will get back to me, but they cannot provide support to my own router.


Because the speed progress on the Eero, it got me interested to further tweak the settings on the Asus router. Noticed that the Eero had IPv6 enabled (even though Bell does not support IPv6 for residential services), and the DNS servers had some changes since last year.

I've tried to replicate the same settings on the Asus router, and for safety, I cloned the MAC address from the Eero's 2.5Gbps port.


At some point, I started getting 1600Mbps down and 1080Mbps up, finally!

--------------------------------------

I switched those settings back one by one, but weirdly the quick/dirty testing results are varied for almost no reason (like anywhere between 800-1500Mbps down, and 400-1000Mbps up), even with the same settings after a reboot. I gave up for the night.

Today, I did further tweaking/testing and found that even if without those setting tweaks, the speed is still great as ever before (1500Mbps down and 1000Mbps up, either on the router webUI, or fast.com/speedtest.net on the PC). It's like everything is back to normal/before.

---------------------------------------
It's hard for me to draw a conclusion at this point. It seems like whatever tweaks VMedia did last night did the trick. I'll keep testing and report back if anything changes. But I'm just so happy that the problem seems to be resolved or at least some major progress.

 

[pricklypunter]

Happy days then

1.5dBmW optical loss on your path is actually pretty good, and well within Bell's parameters. There's zero chance of Bell replacing that drop!
It is a bit of a quandry though for VMedia, they should be supplying you with a replacement gateway, capable of providing the speed that you are paying for on the LAN side.

Speedtests are only a compass, they get you going approximately in the right direction, so don't get too worked up if they don't look great at first glance. You can run a speed test one hundred times and get exactly one hundred totally different results, it's the nature of the Internet and asymmetry

Peak speed, whilst nice to have, is no replacement for reliability, even if that is a tad slower

 

[hys17]

Happy days then

1.5dBmW optical loss on your path is actually pretty good, and well within Bell's parameters. There's zero chance of Bell replacing that drop!
It is a bit of a quandry though for VMedia, they should be supplying you with a replacement gateway, capable of providing the speed that you are paying for on the LAN side.

Speedtests are only a compass, they get you going approximately in the right direction, so don't get too worked up if they don't look great at first glance. You can run a speed test one hundred times and get exactly one hundred totally different results, it's the nature of the Internet and asymmetry

Peak speed, whilst nice to have, is no replacement for reliability, even if that is a tad slower

Yea I feel the 1.5Gbps is really just a marketing BS that the ISP put out and not really intend to support it properly, judging by the equipments they provided... In fact, such plan is no longer offered by them.

I agree speed testing is only a compass and peak speed is meaningless for everyday use. I was totally fine with the previous speed which fluctuated between 1100-1500Mbps. It's just the fact that after an outage which is no fault of my own, I'm no longer getting the same quality of service and the whole time they weren't providing good support, which put a bad taste in my mouth.

The line quality at least has always been pretty decent in my experience, so no complain about that.


By the way, it's been a weird glitch since forever, that after a router reboot, I always have to either reboot the ONT or disconnect the ethernet from the ONT to the router for a bit, otherwise, the ping loss is crazy high. Can't figure out why and it might just be one of the downsides of using my own gears...?

 

[pricklypunter]

I would take a guess and say it's MAC binding on the ONT Port. You only have a single IP Address assigned, so when it grabs it will bind the MAC address of whatever is connected to it, and thereafter only talk to that MAC address. Sometimes just flapping the connection will reset it, if you give the ONT a minute to catch up, but often enough you need to actually reboot it to clear it and allow a different MAC to bind instead

 

[tgl]

That wouldn't in itself explain the observed symptom, since @hys17 didn't mention replacing his router with something else, only rebooting it. But I bet you're close to the truth. I'm wondering if the router itself changes its WAN-side MAC address during reboot for some reason. If so, it should be possible to turn off that behavior.

A variant of this idea is that the MAC address is stable, but the ONT is grabbing a new WAN IP address via DHCP from the ISP whenever it sees its local connection flap, and then somehow that change isn't reflected to the user's router. The trouble with this theory is that it doesn't explain why a subsequent ONT reboot would fix it.

Anyway, to dig deeper, try checking the router's WAN-side MAC and IP addresses at each step during a reboot cycle, and see if anything changes.