Unusually high data usage megathread

Swap out your Xfinity router/modem with a new one. That solved my crazy, makes no sense, data spike problem that started in September. Went over the limit in Oct, Nov, Dec. As soon as I switched it out my daily usage went from 40-50 back down to around 20 where it usually is. And this is in a house with 2 xboxs, 3 tvs, multiple personal computers, gaming computer, Netflix and Amazon streaming most nights. Goes up a bit on weekends or holidays when teens are on more often but not much. If it's going up and up when you're not even using it then get a new router/modem. I went into the Xfi app and paused every single device.....except the gateway (router/modem) itself....and I was still gobbling up data.

@mollinmark That's an interesting perspective. I don't think its accurate though. My new data surge usage of 1350GB (double what it says i normally use) vanished after I swapped out my year-old Xfinity modem for a new one. Back down to the 650GB range where I have always been for years.

I had ATT for years, never went over 600gb. Started out w/xfinity with the same usage.. then randomly in November, we shot up over a TB and have consistently gone over since. It's now Feb 7th and Xfinity says we have used over 400GB in SEVEN DAYS!!  I have apps that track data usage on my laptops, and they're barely 1gb/day. We do have Netflix, but our usage hasn't changed.

I talked to the "data usage escalation" department in December, and they were no help. Just tried to call again, and was on hold for 30 minutes. SO many threads of people with the same issue. Something about this stinks! The only other thing I did around the time of the increase was purchase the pod signal extender 3 pack, but I've been assured that should have no effect. 

As of January my data usage spiked to over 1TB. 

I never was one to track in the past, but looking at the past 6 months we averaged ~600 GB/month (according to Xfinity's tracking log). It is just my wife and I at the house and we have 10 devices connected - 2x Smart TVs, 2x Laptops, 3x Cell Phones, Nest, Ring and an iPad. 

We use our own ASUS Router and personal Modem. As of 1/31 I turned on the data tracking feature and can track data per device and even down to usage of each app on each device. Since I started tracking, I show that after 9 days I have used 43GB vs Xfinity data usage showing I've used 165GB. 

Ive called and spoke with the "experts" in customer service who told me to just continue tracking but gave no further gameplan or solution. They also confimred that  they cannot see what is consuming the majority of data but only that I've used the 165GB. How can they back up any of their data usage claims if they cannot even supply data to compare against mine?

Has anyone else experienced this and if so have you found a solution? I already had to use 1 free overage month and do not want to pay for data I know I am not using. 

At the rate they are currently saying I am using data I fear I will always be above the 1TB threshold on their books. 

My data usage shot up from 165GB to 300GB in ONE DAY! And I was barely even home over those 24 hours!

Also, I know the meter is not accurate. In one instance, near end of month with one day left, I had almost 200GB free. So I downloaded 150GB in game files. 24 hours later it only showed I used 20GB of data. It worked to my advantage that time, but point being, I know it's not accurate by a long shot.

I don't have any way to accurately track every byte, but I do closely monitor large file downloads. All computers are set to 720p streaming, except living room which is 1080p. But even then it's only a few hours a day at most they get used.

If they're going to charge for data overage then there needs to be an accurate up to minute (heck, even up to the hour) certified meter like with gas or electric companies. Imagine if you went to the gas station and went to put $20 in your car's gas tank, you stop the pump at $20 but it keeps going up for another minute or so for another $5-$10 added on. That's what Xfinity data control is like.

I don't know what I can and can't do any more. Only thing they'll tell me in customer service is I have the option to pay $50 more a month for unlimited internet... That's no a solution to the problem.

The data meter is not accurate.  On January 31 my data meter read 658 gb and on the monring of February 1, 2020 it read 1339 GB and was in red. Not knowing how this could be, I called Comcast and was told that my data meter on their end read 658 and I was not over. I also did not receive an email stating I was over the 1 tb. I asked how can I as a customer truly believe or rely on the data meter and was told were working on it. 

My data meter still reads 1339 gb and not has been fixed. 

I asked to have this documented in my account but I doubt it will be.  Also you cannot screen shot the data meter from a phone using the app. Interesting, so it can't be documented. 

I am writing this to let every one know as I feel the data meter cannot be trusted. 

Caedmom,

The calculator is really just a simple guestimater that totals up "typical" usage rates for certain specific things.  But there's a lot of things it doesn't ask about like torrents, on-line drives or backups, and there's a lot of weird stuff like a program stuck in a loop of downloading the same update or malware.  I don't know what you have on your network, but lots of devices can tell you about their own data usage so that might be a place to start.

Frankokee

Try the meter on the website using a computer – at least then you'll be able to screen capture it.  I'd be curious as to whether that meter matches the app or the internal number that Comcast said they have.  (If that meter matches their internal meter, then it makes sense that you wouldn't get an email – ie: it's just a bug in an app and the app isn't what sends the email.)

I've been looking at this seriously since June last year when I had a problem with unexpected traffic bringing me to the brink of overage.
 
I gotta tell ya.  Never has there been a more wretched hive of swine and villainy as the comcast network. I have over six months of log files, packet traces, usual suspects, known exploit attempts, other really weird TCP/UDP/ICMP traffic with frags, runts, sync requests and packets with bogus flags right down there in the TCP/IP spec mud (invalid packets/crafted packets). Also hostile local subnet traffic from my neighbors virus encrusted machines. In other words, typical internet traffic.

I have extensively banged on my cable modem from remote servers with intrusion software. Flipped settings. Enabled for capture. Redirected for dynamic firewall rules to capture, then analyze. Features on the modem enabled/disabled. There’s only one conclusion.

The firewall on my modem will mask traffic from external sources, and not tell me anything if the remote source is half way clever about it. Its counter will also not report any traffic for intrusion attempts that are outside of what it can report in the log files (full and valid TCP/IP/ICMP packets). Frags/sync/modified runt for example aren’t reported as data. I’d consider the counter on my customer owned netgear router helpful, but not particularly useful.

Two ways to solve it. Pass all traffic from the internet to an internal actual firewall appliance (separate box/laptop/PC), then dynamically block it with adaptive rule sets, or plan B. Plan B is using the modem firewall and it’s “features” such as portscan blocking, but enable port forwarding to an internal firewall low numbered port on a firewall appliance (separate box/laptop/PC) that will dynamically blackhole the external request and hang the offending side script that is port scanning you or otherwise trying an intrusion. When you analyze the traffic, you’ll notice the remote side hangs, their script moves on, and doesn’t target you again for as many as 3 days typically, but they always pop up again.  Such is the weberverse.

With traffic shaping on my side internally, I can get down to under 250G typically with no changes in my usage and I stream stuff heavily. With Xfinity gear, running their firmware, I’m sorry. You’re on your own. I’m not looking at it. I’ve posed suggestions in the past about settings you can look at and how to achieve an internal firewall appliance.

Your problem or theirs? I conclude it’s yours since its your network you are stuck with the bills. Welcome to IT and network administration.

Just an update on my issue. I swapped out my modem, and it seems like the data usage rate dropped right away. It's hard to say for sure, since they are only displaying monthly usage and the updates are delayed, but the first couple of days looks very promising. 

Definitely looks like something is wrong with Comcasts metering. I had to switch our an otherwise perfectly good modem.  Just speculating here, but it could be a simple as someone spoofing my modem's ethernet address, and that's why it gets fixed when I swap the modem. If that's the case, who knows when they are going to guess my new address...

I think this is really bad customer service. First of all, this has to be a known issue for Comcast, but they are not providing support for customers. Secondly, they keep billing with an obviously flawed metering system. That's fraudulent, when the customer has little to no recourse.

I use my own modem, and it's only a modem, not a combined router and modem. Having to buy. a new modem to [possibly temporary] fix their gliches does not make me a very happy customer.

We got the same situation since this year. We used to watch Netflix so we know how much the data we used. However since this year, we stop to use Netflix and our data usage was even higher. We checked with Comcast's support and they only want to push you to buy their new unlimited data plan with 300mb. We are going to BBB as they are not willing to help us to investigate this issue but just trying to sale you more.

Posting a new question because the last reply from Comcast in the megathread says the issue is being investigated as of October 2, 2019 and zero updates.  What's the update?  My bandwidth habits haven't changed over the last several months, but Comcast reports I've gone from less than 200GB a month to 1.1TB in January and now 0.8TB half-way through February.  I stream HD content 1-2 hours a day, music for maybe an hour a day and beyond that it's just some web browsing.  I recognize all devices that use my wifi; none of my TVs or devices are streaming nonstop mistakenly; my computer doesn't have a virus (and isn't turned on enough to be the cause, anyway).  And calling Comcast is useless because they believe they're accurate.  

The meter on the internet says 1024 gb and I still have my 2 courtsey months. This is why no one can trust the data meter from Comcast if they are over or under.