Unusually high data usage megathread

@Molly1232, if it's just you, and you don't stream, it should be fairly easy to track.  Many devices have built-in monitoring of their own that can help, and if that fails, you can just turn a device off for a few days.  Note that because the Xfinity meter says it may not include data used in the last 24 hours, the proper procedure is: Shut device(s) down for at least 24 hours, now check the Xfinity meter and note this number as your starting number.  Now continue leaving these devices shut down for more than 24 hours and look again.  (A lot of people fall into the trap of: I turned everything off overnight or for a day and data still went up!  But because of the 24 hour limitation, this is actually common.)

It's difficult to give any more specific suggestions without knowing what you have or what you do.  Based on your description of yourself, I would think you would have no problem staying under 5-10% of the data cap, so apparently, you're doing something that I'm not guessing.  Of course, it may just turn out to be a program with a bug so you might not initially guess it either.

Last year there was a bug on Comcast's side and there were thousands of people complaining about it here and on other forums.  Now, I'm not saying they couldn't have a bug on their side again, but if you're not one of thousands seeing a sudden change, I would lean towards something on your end. (At least I think it's safer to assume that and start looking for a leak before they start charging.)

I posted this in the pinned "excessive data usage" thread but just noticed its marked as solved/answered. I might be having a similar-but-different issue and thought I'd try making a seperate post to get more visibility. Let me know if there's a better way to get help/advice. Below is my original post:

TL;DR

Any advice on what else to do on my end, or who to contact at comcast that can actually help troubleshoot my current excessive data usage for the 2nd month in a row?

Longer story

I have 1TB monthly plan which has been extended to 1.2 TB this summer. I have not added any devices to my set up (in fact, Ive removed several as we got an ATT hotspot for my wifes Macs - and yes, she removed our home's wifi from her settings), and we have not changed our viewing habits. We were averaging 650-700 Gigs all the way through September. In October I installed a new PS4 game which included some updates so I attributed that months "overage" to that (even though I regularly install or d/l PS4 games), and my total usage for october was 1229 Gigs (this was my one courtesy month for the 9 gigs over lol).

When I noticed my data was at 600Gigs for the first WEEK of November, I shut down the PS4 and started looking for other leaks, and the numbers keep crawling up 50-60 gigs a day. I have tried turning off my main PC for a week, both our cell phones are on LTE, we have local cameras that use the LAN but don't connect to the internet and actually have access disabled (no changes have been made to any of the camera settings), the dedicated security cam PC has done a few regular windows updates but that's "normal" and it is not used to browse/connect to the internet. We have one smart FireTV that is used for either HULU or Netflix and we haven't changed our viewing habits or added any new channels/apps.

So..I'm really out of ideas on what to try next to track this issue down. The only thing connected to the internet currently is the FireTv, a windows laptop that I turn on a few times a week for browsing/not streaming any video, the security cam PC that is only online to get windows updates - we don't even browse on this one, and the PS4 I turned on today to verify settings - it has been off since November 8th. Any other trouble shooting suggestions? Is it possible its an issue on comcasts end??

FYI: We are using our own Netgear router with UPNP disabled, Remote Access disabled, ReadyShare disabled, default PW changed, Respond to pings disabled, and with no changes made except for a firmware update that Comcast pushed  like 2 weeks ago - which is after the daily data usage started increasing.

So you do not have Xfinity TV service (cable)?

If you do, I would look at any and all streaming you or someone else might might be doing. We were actully using Netflix through our Xfinity service instead of through the Smart TV wifi and the data usgae was 3x higher than when we viewed through wifi. We also found Peacock through Xfinity was eating up 5+ GB per hour. No real way to measure any streaming (Internet based) as the data usage does not travle through your modem.

I used a couple of tools to measure data usage through our Modem (Owned Motorola SB6190) via Netgear Nighthawk X6 R8000.

Tool #1 Glasswire. Free tool downloaded to connected Windows PC. This tools does a decent job of showing all connected devices and provides visual data tools displaying data usage at variable intervals (5 minutes, hours, day...). I found that some or all Smart TV data usage did not show up on this tool. 

Too #2 Router Tools: My Netgear router has a Traffic Meter and is accurate. I was able to watch data usage in real-time with the exception of our Xfinity TV's data usage when streaming (i.e. Peacock... anything marked as Internet). 

Our data was always under 600 GB until October where we blew the 1229 GB by the last week of the month. I started using the above mentioned tools on November 1. We stopped all Xfinity internet-based streaming and the result was that we only used 250GB by Nov 15.

I did notice some phone updates pulled 2-3 GB as well as Windows updates were larger than I knew. 

If you only use Xfinity Internet, I would recommend you update all hardware and change all router passwords. I am betting you've already done this but if not, I would just to be sure you don't have neighbors contributing to your problem. 

We do not have cable - we have internet only and use this to stream HULU and Netflix on our FireTv (not the stick). At this point I only have this laptop Im using to research this issue, the security camera PC and the smart TV connected to the internet. I can try to see if the software you recommended is helpful, but unfortunately my router does not have any type of traffic meter. It only has "logs" and "events" unfortunately.

thanks for the suggestions. Im just trying to figure out what the culprit could be since our tech/devices/viewing habits have not changed. I may have to suffer through a tech support call to see if they can provide anymore details (like time of day) on whats changed in the past two months, since my router doesn't have a traffic monitor. Im looking into Glasswire now to see what details on I can gleam using my laptop.

Also  as an FYI - I have access control enabled and dedicated IP addresses for all devices. There are no unrecognized devices or "blocked" devices listed (unauthorized devices, intruders or wifi leeches would show up here).

Forgot to ask - What netgear router are you using if you dont mind? Mine is a netgear modem/router combo and I'd be interesting in switching to something that includes data/traffic monitoring since it would help troubleshoot issues like this. Thanks for your help 🙂

For those writing that this is easy to do (exceed 1.2TB), particularly when normal usage is less than 1/2 of that figure, I would wholeheartedly disagree.  By the very fact that there seem to be a number of folks experiencing the very same issue, during the exact same time period, would suggest something more universally changed - either, something like a number of folks like myself who've recently migrated to Apple's Big Sur, or on Comcast/Xfinity's end, itself.

We've now been working/schooling from home for several months now and, suddently, my data usage exploded, on track toward 2.5x or more of regular monthly usage.  With no equipment changes whatsover, I'm sorry, that's just not possible....unless data is leaking, as I told the Comcast rep!  BTW, the number for this specific issue is 877.807.6581 - their data assurance security group or something like that.  

Moreover, I just checked my eero data consumption and it's 1/3 of what xfinity is saying.  While I have one machine that is occassionaly going direct to the Comcast modem, it's not possible that machine alone is responsible for 800gb, know what I do on it (and, don't) and turning it off every night.

If Big Sur, btw, was running something in the background, however, that would be indicated in my eero data stats, too.  So, again, I'm back to it being on the Comcast end.  To that end, I'm quite frustrated as I've called them twice, you have to be sent to level 2 support which apparently you can't seem to get into a queue for but rather have them call you back.  They told me they tried to reach the last time a couple of times which I told the rep was complete nonsense as I had nothing at all on my call indicator (no record of missed calls, let alone a voicemail).  I'm waiting another time for a call back by this afternoon (anyone want to start a pool?).  I've asked them to provide a complete, detailed log of where my data is coming/going from so that I can diagnose the problem, which rather interestingly, you can't seem to do using the online tools.  Hmmmmm

Please update us if you get any answers on this. I'm going to try contacting comcast tomorrow via the number you provided but am not very optimistic giving their support history. It's very frustrating when nothing has changed on my end but my usage has doubled. I have removed all devices from the network except one smart TV (for HULU/Netflix) thats connected to internet, and one laptop that has access but only for windows updates - and I paused those for 30 days yesterday. The comcast usage is still showing 40+ gigs last night which is close to double what I had been using prior to october. I have less than 280 gigs left in my 1.2 TB left this month and will likely go over at current daily rates. I just can't believe comcast doesn't have a better data usage tracker other than a monthly total bar chart. Thats not very useful when users are trying to troubleshoot data usage/leaks 😞

Be careful with measurements like 40 gigs "last night".  The Comcast meter says it may not include data used in the last 24 hours, so if you turn a device off overnight, you don't know how much (if any) of that actually happened during the night.  Some or all could have been in the preceding 24 hours and data used last night may or may not have shown up on the meter yet. 

Yes you are right. I should have said in the past 24 hours. I turned the last few devices off over 24 hours ago but will have to check tomorrows bar chart to see if that affected anything. It's really unfortunate that we can't see the breakdown of daily usage. Even if it was delayed 24 hours that would go a long way to help track down issues.

I'm seeing intermittent spikes in usage and put a bandwidth monitor on my router. I'm using OpenWRT on a ZyXEL and installed the nlbwmon and luci-app-nlbwmon packages and narrowed down the source to a Win10 box connected to a corporate VPN. I think it's trying to read all the files on a remote share but I can't figure out what's causing it, whether it's a Windows bug or a bug in an app. I opened Resource Monitor and on the network tab it shows a lot of traffic for PID 4 on port 445, which means network share access. Alas, this is happening at the kernel level, and doesn't show me which application is responsible for it.

https://community.spiceworks.com/topic/1811032-high-network-utilization-system-process-pid-4

A secondary source of high usage is animated web ads in Chrome. I'm going to install uBlock Origin, which I use on other machines to drastically reduce ad traffic. Web sites nag me to whitelist them in my ad blocker. I'm not letting them use all my bandwidth if I leave their site open overnight.