How to Troubleshoot Intermittent Internet Dropouts?

[Qs Laptop]

Just checked my modem with the Xfinity/Comcast compatibility tool and it says it is not supported and is "incompatible based on filters." I think "not supported" means it's no longer getting firmware updates. I think "incompatible based on filters" means it's rated for up to 135Mbps download speeds and I'm on a plan with higher speeds.

 

[Qs Laptop]

But the big fix was to replace the antique DLink WBR-1310.
When I say antique, the drop down box for setting an initial date/time stopped at 2012... Simply amazing how much better the whole network ran when I put in a new Netgear Nighthawk AX6. I still have another antique router hardwired downstream from the AX6 and reliability on those connections improved as well.

Wow, that quite an upgrade in routers! How old is that DLink router? 10 years?

I think I'm good on the router, I've got an ASUS AC1900.

The big test lately for a modem-to-ISP test is to check if the cable TV still works. I suspect down in the bowels the cable TV is all IP. If the TV is up, the problem is your side. If the TV is down, it's their side.

Yes, as I mentioned when I've had the internet dropouts I have had the cable TV go down too but only once or twice in the past month or so whereas the internet dropouts have occurred probably 50-75 times in the past month.

The last time the cable TV went out I checked Comcast's website and yes, they said service was down in my area.

 

[Qs Laptop]

Exactly, if you are not having issues at this moment, then that ping is reasonably healthy. That's why you can keep it running in the background, so that when you see issues in performance you can look at the pings in real time.

You mean like this?!!



Wow, can't believe this happened while I'm researching it. That's not typical. This dropout lasted about 2 minutes.

 

[Aerides]

You mean like this?!!

View attachment 43480

Wow, can't believe this happened while I'm researching it. That's not typical. This dropout lasted about 2 minutes.

Can you locate the box outside your house and plug in a laptop and replicate it there? It's possible still it's your router, but that would have me thinking it's your provider connection. If you get it outside, it's for sure "them" not "you"

 

[jollystomper]

Just checked my modem with the Xfinity/Comcast compatibility tool and it says it is not supported and is "incompatible based on filters." I think "not supported" means it's no longer getting firmware updates. I think "incompatible based on filters" means it's rated for up to 135Mbps download speeds and I'm on a plan with higher speeds.

That could be a factor. I had the same modem. I bought it in 2013. It seemed as the speed options increased my internet became more unstable. I upgraded last year to a current, supported modem. My internet speed and availability has greatly improved, in fact I do not believe it has dropped at all since then. Just my experience.

 

[MTB4me]

As mentioned earlier in this thread, it could be your connections. For every co-ax connection, remove the connection and insert/remove half a dozen times. This will clean the internal wire a bit, removing any oxidation. Then screw back together and tighten down. Do this for every connection. And if your cable connection is feeding multiple TVs and associated cable boxes, be sure to do the same at all connections and splitters. Unfortunately, some splitters are installed in attics or crawl spaces, making this more difficult.

Many modems have an administrative interface that will show you current signal levels. You can google cable modem signal levels to see what is the minimum for Comcast in your area. Signal levels can certainly be a contributor to your issue, especially if your house has a number of connections and/or splitters.

Good luck!

 

[Qs Laptop]

Can you locate the box outside your house and plug in a laptop and replicate it there? It's possible still it's your router, but that would have me thinking it's your provider connection. If you get it outside, it's for sure "them" not "you"

I went to the box mounted on the side of my house. Box was "secured" with a zip tie that I cut and then opened the box. Several wasps flew out as they were attempting to build a nest inside the box. Some brake cleaner spray took care of them.

There is no ethernet connection inside the box, just a splitter, so I can't easily check for ping dropouts with a laptop. I used a 7/16" open ended wrench to check connection tightness and they were all tight (or maybe corroded in place?)

There was a plastic card inside that was marked 1-6-17, which must have been the last time the Comcast tech was in there. If I remember correctly I was complaining about the TV dropping out back then and with NFL playoffs coming up I bugged Comcast until they send a guy out to replace the cable from the junction box in my backyard to the box on the side of the house.

I closed the box and replaced the zip tie with a new one while wasps buzzed around. Not fun.



I then checked and tightened every coax connection I could find from where the coax entered the inside of the house to the cable modem. The coax that came into the house from the outside box goes to a splitter and the connection to the splitter was somewhat loose, so I tightened that. I also tightened the connection to the modem, though it was pretty tight to begin with.

I'll keep running the ping test in the background and see what happens.

 

[Qs Laptop]

As mentioned earlier in this thread, it could be your connections. For every co-ax connection, remove the connection and insert/remove half a dozen times. This will clean the internal wire a bit, removing any oxidation. Then screw back together and tighten down. Do this for every connection. And if your cable connection is feeding multiple TVs and associated cable boxes, be sure to do the same at all connections and splitters. Unfortunately, some splitters are installed in attics or crawl spaces, making this more difficult.

I like that idea of burnishing the center conductor by inserting/removing the wire. I will go back and redo all connections using this method. Thanks for the tip.

The only splitters in this line are inside the box on the outside of the house and when the coax initially enters the house.

Many modems have an administrative interface that will show you current signal levels. You can google cable modem signal levels to see what is the minimum for Comcast in your area. Signal levels can certainly be a contributor to your issue, especially if your house has a number of connections and/or splitters.

Good luck!

Yes, I can see the signal levels at my modem's IP address. I will Google for proper voltage levels and compare with what I've got showing.

 

[freedomatlast]

When we moved to a new location in 2015, we had this same type of issue for over a year. After checking all internal connections, and exhausting all other possibilities, I had Comcast come out and they discovered the line from the pole to the house and the associated connections were all bad. They replaced all of it. Then they also asked to go inside the house and check out the internal connections as well, but found no issues. After that, the service was great. But of course, since Comcast can never leave any customer with a totally positive experience, they tried to charge me $300 for the service call (even though all issues were outside the house) which after contacting and filing a complaint with the FCC, they finally dropped. It's ALWAYS a battle with theses people!

When we moved again in 2020, before we even moved in, I had them come out and check the incoming line which was underground and they found it needed to be replaced. They replaced the underground line and associated connections and all has been good so far. This time they did not try to charge me for it.

 

[Qs Laptop]

Yes, I can see the signal levels at my modem's IP address. I will Google for proper voltage levels and compare with what I've got showing.

Checking Cable Signal Levels
In the Downstream section, verify Power levels are within the acceptable range of - 15 dBmV to + 15 dBmV for each downstream channel.


Across the four channels my power levels are:
-16 dBmV -17 dBmV -15 dBmV -16 dBmV

These readings a just a tad out of spec.

My signal to noise ratios are good at 32dB.
My upstream power levels are good at 51 dBmV and 54 dBmV.

 

[Qs Laptop]

When we moved to a new location in 2015, we had this same type of issue for over a year. After checking all internal connections, and exhausting all other possibilities, I had Comcast come out and they discovered the line from the pole to the house and the associated connections were all bad. They replaced all of it. Then they also asked to go inside the house and check out the internal connections as well, but found no issues. After that, the service was great. But of course, since Comcast can never leave any customer with a totally positive experience, they tried to charge me $300 for the service call (even though all issues were outside the house) which after contacting and filing a complaint with the FCC, they finally dropped. It's ALWAYS a battle with theses people!

When we moved again in 2020, before we even moved in, I had them come out and check the incoming line which was underground and they found it needed to be replaced. They replaced the underground line and associated connections and all has been good so far. This time they did not try to charge me for it.

Yep, they are not supposed to charge if they find something wrong outside of the house. I imagine they are trained to try to charge for a service call no matter what, only relenting if the customer quotes them their own policy, as you did.

I also suspect it might be the underground cable running from the "pole" to the box mounted outside the house as I've had this problem before and our neighborhood is teeming with squirrels.

Interestingly, I just heard from my son that he had the exact same problem with Comcast and a tech came out on Saturday and replaced the coax from the pole into the house and replaced the modem as well.

 

[Z3Dreamer]

The router and modem are separate units. If the modem's front panel indicator lights are showing no internet connection I don't think the router even enters into the equation since it is "downstream" from the modem.

Sorry, I missed that in your original post. I amend and extend my comments. If you see the lights go out on your modem, no point in diagnosing the router.

Good luck battling the ISP.

 

[target2019]

Just checked my modem with the Xfinity/Comcast compatibility tool and it says it is not supported and is "incompatible based on filters." I think "not supported" means it's no longer getting firmware updates. I think "incompatible based on filters" means it's rated for up to 135Mbps download speeds and I'm on a plan with higher speeds.

I looked for your model and could not find it. I recall that at some point Comcrap went to DOCSIS 2.0, and that was supported by my SB6183.

That was good troubleshooting by you.

 

[Jerry1]

I had similar problems in the past. Ping was a useful tool to determine if the outage was occurring. However, working with people on this forum and a friend of mine, I learned about a command called Trace. Same as Ping, it’s a command line command. I forget the exact way to use it, but what it did was show the signal as it travels through the internet. I was able to tell clearly that the signal was leaving my house and dropping out at the cable company’s equipment. Sorry I can’t remember exactly how to use it, but it’s worth looking into. If I find my notes from that time, I’ll add to my post.

 

[Aerides]

tracert is the same method as ping, except on the command line you enter tracert instead of ping.

so C:\(your user stuff) tracert 173.xxx.xxx.xx (or url)

it will show if there are particular delays and gaps along the network as well. Some timeouts are normal, even when all is behaving well, because not everything is open and friendly to requests.

 

[gauss]

Just to make sure, have you tried the test with more than one pc and network interface?

 

[Jerry1]

tracert is the same method as ping, except on the command line you enter tracert instead of ping.

so C:\(your user stuff) tracert 173.xxx.xxx.xx (or url)

it will show if there are particular delays and gaps along the network as well. Some timeouts are normal, even when all is behaving well, because not everything is open and friendly to requests.

Thanks. I wasn’t sure if it was Trace but you cleared that up.

 

[Turbo29]

I was having the same problem about two month ago with Cox. Interestingly, about a few weeks into the problems they sent an email saying that upgrades were planned. Finally I received this message,

"As we mentioned in our last few communications, our big service updates that’ll deliver a stronger, faster connection require a small scheduled outage. And today is the day we start work.

This means you won’t be able to use your Cox services and internet-connected devices for the few hours we work to complete service. We know this is an inconvenience, so we’ll do everything we can to get you back up and running ASAP."


The outage was only about an hour but the next day all of the problems vanished. So your problem may be your provider, not you.

 

[Qs Laptop]

Just to make sure, have you tried the test with more than one pc and network interface?

Yes, we lose internet service on our phones as well as PC.

 

[Qs Laptop]

I looked for your model and could not find it. I recall that at some point Comcrap went to DOCSIS 2.0, and that was supported by my SB6183.

That was good troubleshooting by you.

Thanks for that. It's gratifying to hear it from you, whom I consider to be one of the top tech resources on ER.

 

[Jerry1]

So your problem may be your provider, not you.

It’s almost always the provider. Why would everything start going wrong be the fault of the homeowner. It is far more likely that the homeowner didn’t change anything - that these things just started happening for no reason. It seems unlikely that the homeowner’s equipment would just up and go bad. Of course, the line running into the house could have certainly got damaged and there are times when the home owner messes with something and causes an issue. More likely is that something happens at the providers end. Their equipment is out in the elements, they are often making programming changes to their equipment, their equipment is taking on a lot more traffic. . .

Yet they walk in your house and act like there’s no way it could be their fault. Man I can’t wait until fiber is available in my area. My understanding is it’s either on or off. Much easier to diagnose.

 

[ERD50]

Checking Cable Signal Levels
In the Downstream section, verify Power levels are within the acceptable range of - 15 dBmV to + 15 dBmV for each downstream channel.


Across the four channels my power levels are:
-16 dBmV -17 dBmV -15 dBmV -16 dBmV

These readings a just a tad out of spec.

My signal to noise ratios are good at 32dB.
My upstream power levels are good at 51 dBmV and 54 dBmV.

Thanks - I wasn't aware that info was available, but I found it for my modem/router, and the numbers look to be in-line with the data I found on the web.

-ERD50

 

[Turbo29]

It’s almost always the provider. Why would everything start going wrong be the fault of the homeowner. It is far more likely that the homeowner didn’t change anything - that these things just started happening for no reason. It seems unlikely that the homeowner’s equipment would just up and go bad. Of course, the line running into the house could have certainly got damaged and there are times when the home owner messes with something and causes an issue. More likely is that something happens at the providers end. Their equipment is out in the elements, they are often making programming changes to their equipment, their equipment is taking on a lot more traffic. . .

Yet they walk in your house and act like there’s no way it could be their fault. Man I can’t wait until fiber is available in my area. My understanding is it’s either on or off. Much easier to diagnose.

One time the tech came out, measured the signal strength, and then walked across the street and opened the little cylindrical box that has their wiring. This was back when they still had analog cable TV for the basic channels, which could be stolen. He told me that someone (and pointed to the house) was stealing cable TV and that they had partially severed my coax wire when they did it.

He said, "Watch this" and then yanked out the cable that went to the offending residence. Someone came outside the house, looked at the truck that said "Cox" on the side and asked, "Um, how much does cable TV cost?" Tech said that always happens when he cuts a freeloader off.

 

[ERD50]

Originally Posted by Qs Laptop View Post
There is CenturyLink (formerly Qwest) but the fastest service available at my address is 80 Mbps.

Unacceptable.

I’d been experiencing similar problems here with Spectrum (cable) and before that in the midwest with Comcast (also cable).

The only thing that seems to have set it right was switching to fiber. I guess many old coax cable systems are deteriorating with time and lack of maintenance.

What's unacceptable? 80 Mbps?

Even a 4K video stream 'only' needs 25 Mbps.

https://www.consumerreports.org/broadband/internet-fast-enough-for-streaming-broadband-speed/

Netflix and other streaming companies say your internet service needs to run at least 5 Mbps for streaming high-definition shows and movies, but that’s sufficient for only one user at a time. As you can see from the chart above, 18 Mbps is really the minimum speed most homes will need for streaming 4K movies and TV shows from Amazon Prime Video and Netflix. (Netflix recommends a 25 Mbps speed for streaming 4K, while Amazon says you’ll need at least 15 Mbps for the highest-quality video.)

-ERD50

 

[USGrant1962]

Just checked my modem with the Xfinity/Comcast compatibility tool and it says it is not supported and is "incompatible based on filters." I think "not supported" means it's no longer getting firmware updates. I think "incompatible based on filters" means it's rated for up to 135Mbps download speeds and I'm on a plan with higher speeds.

Coincidentally I've been having similar problems. I've had to reboot my SURFBoard SB6141 about once a week for the last month. Sometimes no internet, and one time running at 10% speed. I found the same "not supported" info on Xfinity so bit the bullet and replaced the modem.

The SB6141 was also limiting my DL speed to about 285 Mbps on my 300 Mbps plan (285 is top speed of that version of DOCSIS I understand).

Last week ordered a refurb Netgear CM1000 for $99 (it is $129 today) on Amazon. I just installed it on Saturday but so far so good. SpeedTest.net shows ~350 Mbps down.

I went with refurb because these things are plug it and forget it. If it is DOA it is a simple exchange at Amazon. The refurb was actually from Netgear with a Netgear refurb warranty card included.