Inconsistent speeds ? Can ONT go bad?

Hi all, i have noticed speeds starting to be a bit inconsistent. We're on the 900 package and are used to getting speeds of 1gb+ - which is great and expected. But sometimes it drops right off to 90mb. Uploads remain constant at 100+. I have noticed that by plugging in the fritz box (we use our own nighthawk router) and resetting the ont. Then plugging back into the nighthawk it seems to fix it.. although it seems to be getting more frequenet and just by rebooting the ONT seems to fix it... can ONT box's start to fail ? thanks in advance.

All electronic devices can start to fail but I don't think it is a common issue with ONTs. I have never had to power off my ONT, I do tend to have to retart my router every 4-6 weeks when the wi-fi starts to get tempremental.

Unplugging the router from the ONT or resetting the ONT will both have the same effect of dropping the connection - when the new conection is made it is quite likely that you will reconnect to a different pop (which may or may not also result in switching your roiuting between London and Manchester).

Depending on where you are it is possible that there is insuffiocient capacity in your local area resulting in congestion at peak times .

In reply to a post by nazzer:

Hi all, i have noticed speeds starting to be a bit inconsistent. We're on the 900 package and are used to getting speeds of 1gb+ - which is great and expected. But sometimes it drops right off to 90mb. Uploads remain constant at 100+. I have noticed that by plugging in the fritz box (we use our own nighthawk router) and resetting the ont. Then plugging back into the nighthawk it seems to fix it.. although it seems to be getting more frequenet and just by rebooting the ONT seems to fix it... can ONT box's start to fail ? thanks in advance.

I'm assuming you are on the Open Reach service on zen. with GP you share a connection with up to 30 people, on a 2.5gbit connect (2.5 gbit down and 1.25gbit up). This means sometimes the connection speed is contended, so you may find you don't get the full fat 1gbit download

While there probably are fault modes for an ONT which cause it to be intermittently crabbit, it is far more likely that any failure would degrade its behaviour fairly consistently or cause it to fail quite solidly

I would also try replacing the cable between the ONT and the Nighthawk, with a good quality Cat 6 cable. Worth a shot ?

There *are* potential failure modes that cause a 1G ethernet link to negotiate down to 100M.

This could be a bad cable, as has been suggested, or it could be a bad connector on either the ONT or the WAN port of the router. More unusually it could be static or lightning damage (this has been observed)

As suggested: replace the cable first. Then try a different router for a while. If that shows the problem still then the ONT is suspect.

(No need for Cat6; Cat5e is perfectly fine, especially on such short links. But good quality, yes).

In reply to a post by nazzer:

Hi all, i have noticed speeds starting to be a bit inconsistent. We're on the 900 package and are used to getting speeds of 1gb+ - which is great and expected. But sometimes it drops right off to 90mb. Uploads remain constant at 100+. I have noticed that by plugging in the fritz box (we use our own nighthawk router) and resetting the ont. Then plugging back into the nighthawk it seems to fix it.. although it seems to be getting more frequenet and just by rebooting the ONT seems to fix it... can ONT box's start to fail ? thanks in advance.

90mbits/s or 90mbytes/s ?

In reply to a post by candlerb:

There *are* potential failure modes that cause a 1G ethernet link to negotiate down to 100M.

This could be a bad cable, as has been suggested, or it could be a bad connector on either the ONT or the WAN port of the router. More unusually it could be static or lightning damage (this has been observed)

As suggested: replace the cable first. Then try a different router for a while. If that shows the problem still then the ONT is suspect.

(No need for Cat6; Cat5e is perfectly fine, especially on such short links. But good quality, yes).

The ONT fault I had years ago (following lightning strike / surge and back feed etc) - nuked the ONT copper port in that it refused to negotiate above 100Mbps. It was evident very quickly as up and down just capped out predictably. Seemed reasonable at the time that the ONT had suffered like a lot of other kit we had that was either fried beyond recognition or just severely impaired by the strike / surge.

Doesn’t really sound like this is the OPs issue as this seems more variable throughput wise, up to full line rate - so ONT may have an issue, just not this particular issue.

If an ONT reset clears up the problem, then a fairly safe assumption is that the ONT is somehow faulty rather than cabling or router etc.

In reply to a post by Pheasant:

If an ONT reset clears up the problem, then a fairly safe assumption is that the ONT is somehow faulty rather than cabling or router etc.

Only if a router reset or a cable plug/unplug *doesn't* fix the problem.

i.e. if simply bouncing the link clears the problem, it could be at either end. If the problem can *only* be cleared by a hard reset of the ONT, then I'd agree ONT most likely at fault.

Yes. Ceteris paribus