Could this indicate a failing modem?

General discussion related to Cable Modems, DSL, Wireless, Fiber, Mobile Networks, Wireless ISPs, Satellite, or any other type of high-speed Internet connection, general issues and questions here. Review and discuss ISPs as well (AT&T / SBC, BellSouth, Bright House, CableOne, Charter, Comcast, Covad, Cox, Cablevision / Optimum Online, TMobile, Verizon FIOS, Shaw, Telus, Starlink, etc.)
Post Reply
jbaugh
New Member
Posts: 1
Joined: Mon Apr 12, 2021 11:29 pm

Could this indicate a failing modem?

Post by jbaugh »

I have been troubleshooting my home network for the past 2 days. The problem has to do with inconsistent network behavior manifested when using a browser to navigate the internet.
I have a relatively fast service with Comcast/Xfinity (600/18). If I go to a website in a browser there is normally a short pause between hitting the "go" button and the appearance of the website page in the browser, usually between ½ second to 2 seconds. But then when I enter another url in the browser and hit the return or go signal, often, but not always, the progress bar moves very slowly in the browser and it may take 15- 30 seconds for that new page to begin loading. Sometimes the page never loads. Interestingly, if I place the cursor in the browser url window after the url and hit the return button again it often forces the page to load quicker. This happens with multiple browsers. The other thing I notice is that when I try to test my internet speed on various speed test sites, there is often a long delay before the download begins and often I get an error message that the test failed for some reason having to do with a socket? I've viewed the upstream and downstream power ratings of my Arris modem and they seem within the limits felt to be normal. I've switched out my router to test with an old router and I've demonstrated the same behavior, thus ruling out my router as the problem. This same behavior is seen on all 4 of my household computers. and even on my iPhone when browsing. It seems to me that it is either a problem with my modem or some problem on Xfinity's end. I'm not sure how to proceed short of buying a new modem to see if that fixes the issue. Any thoughts will be greatly appreciated.
John
User avatar
Philip
SG VIP
Posts: 11606
Joined: Sat May 08, 1999 5:00 am
Location: Jacksonville, Florida

Post by Philip »

My initial thought was that you have an issue with your computer/browser, some malicious browser extension or such, but if you are getting this across multiple clients with different browsers it must be your line.

I would do a traceroute to a remote server to see if there is excessive lag spike in the first hops that are owned by Comcast and near you.
I would also try to use different DNS servers, try Google's or CloudFlare, for example, here is a list: https://www.speedguide.net/faq/what-alt ... -i-use-128
You can set this in your Network adapter, or, in your NAT router for all clients.

If that issue is always present Comcast should be able to troubleshoot it, this does not seem like acceptable level of service. If they still charge modem rental fees you can always buy your own, but I doubt this is the culprit.
Linux is user friendly, it's just picky about its friends...
Disclaimer: Please use caution when opening messages, my grasp on reality may have shaken loose during transmission (going on rusty memory circuits). I also eat whatever crayons are put in front of me.
๑۩۞۩๑
User avatar
Norm
SG VIP
Posts: 14195
Joined: Tue Mar 27, 2001 12:00 pm

Post by Norm »

On top of what Philip has stated another thought crossed my mind.

quote "4 computers and and an IPhone"
And possibly more phones?

Are the PC';s wired or wireless?

The "thought" is about interference with so many devices using wireless. Also if this is the case and it is an interference issue within your home, after the "short delay" when doing speed tests do you get a good speed report?
If the speed report is good, then I'd look into interference possibilities, like:
Did you just install a new device, or move a device to a new location that may have started this issue?
Is there any devices close to any EM sources, like speakers, electric motors etc
Are all devices using the same channel?
Lots of nieghbors using wireless too?
Google 'wireless interference' for more possible reasons for interference.

Just a thought, hope it helps you in some way.
Post Reply