How to Troubleshoot Intermittent Internet Dropouts?

[steelyman]

What's unacceptable? 80 Mbps?

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

-ERD50

The Comcast service as reported.

 

[Qs Laptop]

Still running ping in the background an haven't had an internet drop since I tightened two coax cable connectors.

Well, I'll be buying a new modem anyway. Turns out my Xfinity/Comcast internet plan had speeds up to 300 Mbps but my old Motorola Surfboard SB6121 is limited to a top speed of 135 Mbps (though speedtest.net showed 139 Mbps.) Turns out my modem has been unable to utilize the top speeds that Comcast was providing. I think when I bought this modem the internet speed provided was 150Mbps, then they upped it to 300Mbps at no extra charge a couple years ago.

As I've been streaming more with my Roku, I've been meaning to downgrade my Comcast TV plan and finally did so today. I eliminated a tier of channels and also upped my internet speed to 600Mbps. This move netted me $51 in monthly savings. So I'm shopping for a new modem.

 

[MTB4me]

Seeing that you have a 3-way splitter in your service box, one option to improve signal strength is to cut back to a 2-way splitter or even remove the splitter altogether if you are only using 2 or 1 in-house coax connection(s). Doing that will put you back within spec without having to get Comcast to replace the cable from the pole. Not an option, however, if you need all 3 connections.

Either way, if you haven’t already, disconnecting and reconnecting at the junction box might help if oxidation has built up on those center wires. Oh, and if you have some fine grit sandpaper, maybe 400 or so, you could use that to remove the oxidation on that center conductor more efficiently.

Nice working checking on those signal levels. You are definitely at the margins.

 

[MTB4me]

One more thing to consider. Since your setup is at the lower limit for signal strength, then your signal may be susceptible to interference. If you see any more ping drops, you might be able to correlate them to a motor starting somewhere close to one of your coax feeds. Or a fluorescent light fixture or microwave oven. All sorts of similar things could affect your signal when you’re at the lower limit.

 

[target2019]

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

So you'll need a modem, and it sounds like your router is recent and won't be a problem.

 

[Qs Laptop]

Seeing that you have a 3-way splitter in your service box, one option to improve signal strength is to cut back to a 2-way splitter or even remove the splitter altogether if you are only using 2 or 1 in-house coax connection(s). Doing that will put you back within spec without having to get Comcast to replace the cable from the pole. Not an option, however, if you need all 3 connections.

Yes, this is a good idea. I know that the orange coaxial cable goes back underground and goes to the back of my house, into my home office in the basement where it gets split with one line going to my modem and the other line going to the cable box in our family room one floor above.

One of the white coaxial cables coming off the 3-way splitter goes directly inside the house, into the basement and goes to a cable box.

The other white coaxial cable coming off the 3-way splitter goes all the way up the outside of our two story house, into the attic, and eventually gets dropped through the master bedroom's closet and is UNUSED. I could disconnect that cable and install a 2-way splitter inside the box outside the house. Any recommendations for a good 2-way splitter suitable for harsh conditons? If I go this route I don't want to go cheap on this component.

Either way, if you haven’t already, disconnecting and reconnecting at the junction box might help if oxidation has built up on those center wires. Oh, and if you have some fine grit sandpaper, maybe 400 or so, you could use that to remove the oxidation on that center conductor more efficiently.

So far there has not been a blip in the ping test since I tightened those coax connectors. But if I start getting drop outs again, I'm definitely going back into the box and cleaning the center conductors on those connectors. I'd replace that 3-way splitter with a 2-way at the same time.

Nice working checking on those signal levels. You are definitely at the margins.

It will be interesting to see if those signal levels are adequate with a new modem. Looking at blowing that dough and getting a Moto MB8611.

 

[Qs Laptop]

So you'll need a modem, and it sounds like your router is recent and won't be a problem.

Considering blowing that dough on a Motorola MB8611. It's way more than I need right now but who knows in 2 years? My new internet plan is 600Mbps, though 1.2 GB is available; this modem can handle up to 2.5Gbps.

 

[target2019]

Considering blowing that dough on a Motorola MB8611. It's way more than I need right now but who knows in 2 years? My new internet plan is 600Mbps, though 1.2 GB is available; this modem can handle up to 2.5Gbps.

You're right, we don't know what's down the road.
I'm out of date on the latest, so I read this article:
https://litecomparison.com/motorola-mb8611-vs-arris-s33/

Can't say what I'd buy. Maybe look at last year's models.

 

[ncbill]

I had my own equipment...combo modem/router...was getting 75 down.

Switched to the free modem from Spectrum & added a newer router.

Now get 200-250 down, officially paying for 200 down.

 

[Jerry1]

I had my own equipment...combo modem/router...was getting 75 down.

Switched to the free modem from Spectrum & added a newer router.

Now get 200-250 down, officially paying for 200 down.

I use the modem from Spectrum also. I look at it as their responsibility to get the signal to my router. I don’t want them telling me that it’s my router any time something goes wrong.

 

[MTB4me]

Probably can’t go wrong with this GE 2-way splitter from Amazon:

https://www.amazon.com/GE-Amplifiers-Compatible-Connectors-33526/dp/B0054EILOE/

Gold plated for good corrosion resistance.

 

[MTB4me]

And I’m not too surprised at the signal levels you are seeing given how many splitters are in your system. You are on the edge of needing an amplifier or signal booster at the cable feed end.

If things stay stable, then call it a win. Otherwise, at least get one of those cable runs out of the equation.

 

[Qs Laptop]

And I’m not too surprised at the signal levels you are seeing given how many splitters are in your system. You are on the edge of needing an amplifier or signal booster at the cable feed end.

If things stay stable, then call it a win. Otherwise, at least get one of those cable runs out of the equation.

I'm thinking of getting that GE 2-way you suggested but buying the 4 pack. I would replace the 3-way in the outdoor box and the 2-way in my home office. Simply getting a new splitter in the box outside and cleaning up the center conductors of the coax should do wonders.

The existing 3-way splitter has 3 coax cables coming out of it, but only 2 are connected to anything. The other one runs into the house but there is nothing connected to it. Does an unconnected coax cable introduce signal loss at the other connections? Or is the idea that a 3-way splitter inherently has more loss than a 2-way? (Most 2-way splitters have a 3.5dB loss at each connection.)

 

[MTB4me]

The 3-way splitters are going to be about 5.5dB down on each port. For every 3dB, the signal is cut in half. And that unused coax could potentially act as an antenna at the far end, depending on what it’s close to with respect to interference sources. If you do nothing else, you could consider putting a 75 ohm termination on your unused coax cable ports.

I like your idea to replace your existing splitters, particularly if they are older or not gold plated. Those newer ones should help somewhat with oxidation, though the center conductor of the coax cable will still be copper.

 

[target2019]

At my location the fibre is terminated in a large "bullet" near the curb. Then coax runs underground to the garage, and is split inside the garage.

I don't know all that you have, but you'd want to know what's going on all the way from the curb before removing splitters. I remember in the past that techs would make changes in curb termination to boost signal, turn it down, etc.

Removing the 3-way splitter sounds like a good idea, though. I personally wouldn't have removed the seal to open the box. But now that you have, it's worth a try with 2-way splitter.

 

[Bamaman]

Comcast is simply not the operation they should be. Part of being in the NBC family.

My Comcast cable simply wouldn't work, and the service people couldn't figure it out. My friend is friends of the local service manager at Comcast, and he got him to look into the problem.

Come to find out, there was another house in the country with my house number and the same street name. Comcast had cable service going to a house in another city/state.

Hard to believe that Comcast began as the cable television franchise in Tupelo, Mississippi. And it's grown into the totally incapable operation it is. No wonder they're fighting keeping up their customer base numbers.

 

[Qs Laptop]

Update:

Got the new Moto MB8611 modem and connected it. Using the Xfinity app attempted to activate it. Typed in the new modem's MAC address and followed all instructions. Failed to connect.

Repeated the process. Failed to connect. All front panel lights were steady on and the proper color except for the ethernet status light which was blinking green.

Called Comcrap. Suffered through the phone rep's troubleshooting script. She took the MAC address of the new modem and entered it into the system from her end. Then had me power cycle the modem. Again, failed to connect.

A service technician is coming out tomorrow at no charge to check the quality of the signal on the coax running from the "bullet" in the corner of my lot into my house. I presume he will install a new splitter. If so, I will ask him do disconnect the unused coax running to my 2nd story and put in a 2-way splitter.

Meanwhile I had the phone rep put my old modem's MAC address into their system while I swapped out the new modem for the old modem. Old modem works so I'm back online.

My theory? The new modem requires a higher signal voltage to operate. I posted the voltage readings I obtained from my old modem further upstream in this thread and they were just barely within specs. I suspect the signal is not strong enough to engage the new modem.

I did attempt to see the voltages with the new modem connected but I couldn't get to the gateway address.

 

[Qs Laptop]

UPDATE:

Service technician was out today. He took voltage readings and showed me that my signal levels were borderline low (which I knew from checking the levels myself online.) He went out to the tap and found an egress filter in my coax line. This is used to prevent noise that might be present on my line from getting onto the neighbor's connections. He said that could be dropping the signal levels a bit.

At the box mounted on the side of my house he disconnected the cable running to the top floor of my house, removed the 3-way splitter and installed a 2-way splitter. Changed out all connectors on all coax cables. Inside the house he changed all the coax connectors en route to my new modem.

I now have strong voltage levels so I think my days of having internet dropouts are over. I've also got the fastest internet speeds I've ever had at my house.

 

[target2019]

Sounds great. Glad the tech went into every part from the curb to your modem.

 

[steelyman]

Way to go! Your persistence paid off!

 

[W2R]

Excellent!! Congrats.

 

[RetiredAndLovingIt]

My son in law who works in IT told me that if you can still print over your home network when the internet is down then the router is not the problem.
I've been having problems all day with basically the same problem as Q. I've pinged it and there is definitely an issue so tomorrow I'll go to Spectrum and get a new modem and see if that fixes the problem before I call tech service. I'm also not getting the speeds I'm supposed to.
By the way I was able to print when it was down, I' curious if the experts here agree that it's a good test to eliminate the router as the problem?

 

[Qs Laptop]

My son in law who works in IT told me that if you can still print over your home network when the internet is down then the router is not the problem.
I've been having problems all day with basically the same problem as Q. I've pinged it and there is definitely an issue so tomorrow I'll go to Spectrum and get a new modem and see if that fixes the problem before I call tech service. I'm also not getting the speeds I'm supposed to.
By the way I was able to print when it was down, I' curious if the experts here agree that it's a good test to eliminate the router as the problem?

When you are printing over your home network you are using the wifi network only. The wifi network is created by the router. You're not printing over the internet, you're not using the internet at all.

When/if your modem drops out that means you're not connected to the internet, therefore your phone can't browse the internet even though it's got the same wifi signal it's always had from the router.

So, yeah, if you can still print when the internet is down that means your router's wifi function is still working. It's your modem that is not working.

 

[target2019]

My son in law who works in IT told me that if you can still print over your home network when the internet is down then the router is not the problem.
I've been having problems all day with basically the same problem as Q. I've pinged it and there is definitely an issue so tomorrow I'll go to Spectrum and get a new modem and see if that fixes the problem before I call tech service. I'm also not getting the speeds I'm supposed to.
By the way I was able to print when it was down, I' curious if the experts here agree that it's a good test to eliminate the router as the problem?

If you can print, that's a good sign. If it's wifi connection then you've proved that that wifi is good.

Routers and modem have two interfaces, or sides (at least). Yours may be internet -> modem -> router -> LAN devices. If you can print on the LAN, it is possible that the connection between internet -> modem, OR modem -> router is not good. In most cases it's a good assumption--that internet is bad, but you can have a problem between modem and router.

If you can print locally it does mean your LAN is probably ok, but this does not isolate the problem to the internet.

I had an older 2nd router on upper floor. Periodically it would go into a zombie state, and I needed to reboot that router. Computer attached directly did not get internet, but the problem was isolated to the specific router. I could print through that router to a printer in same room (Wifi or direct), but the problem was not the internet. It actually was the old router (which eventually got replaced).

 

[KarenF]

If you are not sure how old your modem is I would replace it. Replacing my modem and switching to a mesh router took care of every internet issue we had.