I live with my wife and daughter and our internet usage habits have not changed in recent months. In December we used 300GB which is about average for the past year. Suddenly, without any change in our habits, it went to exceeding our cap of 1024GB. If it continues at this rate, we'll be around 1200GB this month. That's nearly 4 X previous months!
I called comcast and they told me I'm either streaming more (thanks for the suggestion...hadn't thought of that) or someone outside our home is using our wifi. No one is using our wifi outside our home. We barely get a decent signal in our home. If anyone was able to get close enough to connect, and manage to get past our wifi security, and not be detectable (I can read the router logs), I don't think it would even be possible to use that much data if they streamed it 24 hours a day with the poor speeds they would get from outside our home.
That was all they could offer. No explaination on how the meter data. No offer to look into specific days or times of the day when usage was higher. Nothing. Just "change your wifi password, and dno't stream as much." We are currently being charged for excess data.
Comcast is counting all the data that is going through your modem (up/down). They can't see specific device or application data as they don't track your usage in that manner.
The most common reasons for increased data usage are:
1) Streaming video (I know they told you this already)
2) Unsecured Wi-Fi (I know they told you this already too)
3) Infected machine - it's possible you have a device that is either on the fritz or has become infected. Make sure you do a malware/virus scan on every device.
Many routers have the capacity to track data usage across specific devices or applications. Unfortunately, Comcast supplied devices do not have that capability. If you are using your own router, check if that's a feature. If you are not, consider buying your own router.
One way to troubleshoot data usage is to schedule a period of "digital silence". It's not always practical, but unplug your modem for a time and see if your data increases. Keep in mind that the meter is not in real-time.
These folks deal with data usage inquiries, I'm guessing they are who you talked to already?
Customer Security Assurance
Also, you have two "courtesy months" where you can exceed the limit and not get charged extra.
I am working through this exact same issue right now. The Comcast representative I spoke to (ater being on hold for 30+minutes) was not helpful at all. She offered basic advise and comments like "perhaps your neighbor has your wifi password" or "did you increase your streaming of videos from Netflix?". I asked her for a report that showed by usage by day for each month so I could see what might be occuring. She said she could not provide that. I asked her if we could look at usage by connected device so I could see if I had one offeding devices, she said she could not. I asked her if I could see usage by type of contect (social networking, gaming, video streaming, etc., she said she could not. What is interesting I can get all of this on my Verizon wireless plan and I can download a report that shows my data usage by hour of day. I finally just told her that if Comcast cannot provide that data to prove they are not double counting my usage then I am not going to pay the bill. She didn't seem to care. Basically, they hold the keys and you are on your own. They have no incentive to help you. I am sure their intent is to just get you moved to the higher tier plan.
I get where you're coming from, but there just isn't any way to track your usage on that level from Comcast. I'm not privy to Comcast's business decisions, but I'm guessing it's that way intentionally. They would really be pushing the bounds of acceptable privacy rules if they were monitoring your specific device usage and application usage. Most of us would not be comfortable with our ISP having that information. If you want a traffic analyzer, a lot of routers have that ability --you would just need to purchase your own and authorize the software.
I use my own router and it tracks total data (which agrees reasonably closely with Comcast's meter - maybe the same once you allow for the fact that they don't update at the same rate) but it does not show individual devices. However, many of my devices track their own data. Ie: while I used 900MB in the last day according to the router, the PC I am typing on used 300MB since then. I also have a couple of laptops that track themselves in the same way. Tablets and phones depending on OS generally either have data tracking built-in somewhere or you can download an app. With smart TVs, TV appliances and the like, you may or may not have this (maybe in the future check for that when shopping). I know some devices like Rokus have hidden "advanced" screens that you can learn about on their forums.
Or buy a router that tracks this stuff by device. I've heard of routers that do that. I think Asus routers do that, and I've heard of open source firmware for routers that may do it. Some people build their own router out of an old PC and open source software.
Of course there's also the classic method of turning selected devices off for a few days at a time and seeing what that does to your data usage. On phones, you can simply turn off the wi-fi and see how much your comcast use goes down (and how much your cellular use goes up.)
By the way, in the case of streaming, simply replacing an HD TV with a 4K TV can send your data through the roof, simply because your streaming service/device simply assumes on your behalf that you want much bigger 4K streams now.
Hello All -- Our Security Assurance team handles all data related questions. They will have more information available for you. You can reach them at 1-877-807-6581.