r/technology • u/Tech-100 • Aug 18 '26

Networking/Telecom Comcast is turning millions of its routers into motion detectors

https://www.theverge.com/news/981381/comcast-xfinity-shield-wifi-motion-sensing
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u/WiglyWorm Aug 18 '26

Comcast. Comcast will turn this on. The question is whether you want its "on-ness" exposed to you or not.

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u/bert1589 Aug 18 '26

They’ll then also turn it back on after a forced update to the modem / router. Looking at bridge mode and ALG settings as an example. It’s borderline hostile

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u/SIGMA920 Aug 18 '26

This is why you use your own router, probably will be better than what they install anyway.

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u/IM_INSIDE_YOUR_HOUSE Aug 18 '26

That's why they introduced legislation recently that'll severely limit the modem and routers people can buy.

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u/SIGMA920 Aug 18 '26

Should be able to bypass that by buying from another country without that BS.

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u/WiglyWorm Aug 19 '26

Buy a TP-Link router and flash it with DD-WRT

* warning you have a high risk of bricking your router when you try to update the firmware

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u/WiglyWorm Aug 18 '26

Indeed. I bought my own router and modem.

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u/J_Bright1990 Aug 19 '26

Ok I need some real advice, or rather a tutorial. How do I activate a new modem and router on my service?

I remember in the past it had to be plugged into a computer full time. Is that still a requirement?

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u/WiglyWorm Aug 19 '26

No worries. You asked the right person, it's actually really simple. I'm gonna give you an info dump and you can ask any follow up questions you want.

First of all a modern modem isn't a modem. MODEM stands for "modulator de-modulator" and it was the device that used sound into 0s and 1s for computers. Those are the ones that were plugged directly into computers. They were just another input device for the computer.

Modern cable, satellite, or any other non-analog form of internet access uses the term "modem" because it's what everyone is familiar with, but in reality it's just a small computer with a serial number that it knows how to show an internet provider, and then the internet provider can check if that modem is authorized and send it internet if so.

All that said, here's the point:

Your ISP is required to let you bring your own device, so you can contact them in your preferred manner and ask them what makes/models of modems are compatible. It might be listed somewhere on their website somewhere if you dig, but honestly I wouldn't be surprised if they made it very hard to find or just don't provide the list without making you contact customer support.

So get the list, then run up to a Microcenter if you have one near you or just go online to microcenter and find a compatible model modem.

Your product options would be to get a modem/router in one, or a standalone modem and a standalone router. What works best for you is up to your individual needs, the size of the space you have, if you need options like repeaters so you can have coverage through the whole house, etc etc. A lot of this stuff you can buy piecemeal, and it's generally all standards based and interoperable.

In general I think for the money spent you get a better deal buying a basic modem and spending the money on a nicer wifi router, but if you're not going to set up a separate network for untrusted devices like your alexa home speakers or your lightbulbs or your enshitified wifi dishwasher then you definitely don't have to break the bank.

If you want a brand recommendation from me, I say buy a TP link, set a user name and password you'll remember on the router itself by following the instructions to point your web browser at the router config page (usually you go to something like http://192.168.1.101 or something. Type type ipconfig into your terminal and look for your default gateway address. That's what you want to go to in your web browser.

Once you get it home and get it hooked up, call your cable company and tell them you bought a modem and a router and you no longer need to rent theirs.

They will have you read a few numbers off the back of the modem, enter it into their system, and you will have internet.

Return the modem/router you were provided to your internet provider and make sure they stop charging you the rental fee. Your internet bill will go down.

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u/Syzygy2323 Aug 19 '26

It most certainly is a modem. Cable systems modulate signals onto the cable to transmit network data. It's not the same type of modulation used by older telephone modems, but it still requires a modem to modulate and demodulate the signal on the wire,

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u/WiglyWorm Aug 19 '26

Modern Internet uses digital signals. There is no modulating in any sense of the word MODEM, that is, there is no digital -> analog-> digital conversion

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u/aardvarkjedi Aug 19 '26

Cable internet services use QAM-64, -256, and -4096. QAM is Quadrature Amplitude Modulation, and it is indeed analog modulation of digital signals on the wire.

Read about it here: https://en.wikipedia.org/wiki/Quadrature_amplitude_modulation

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u/bert1589 Aug 19 '26

Yeah. Finally convinced customer to pay for their own modem

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u/BearsBearsBears_wooo Aug 18 '26

My router is in a storage room in the basement and I have FIOS. still sucks though

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u/-awinisawin- Aug 18 '26

it doesnt matter where the router is. if you have wifi waves bouncing around your house. they can be used to detect motion.

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u/WiglyWorm Aug 18 '26

making it wired and putting it in a faraday cage or otherwise blocking the signal is the only way to prevent it.

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u/hikeonpast Aug 18 '26

Just buy your own router

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u/BearsBearsBears_wooo Aug 18 '26

I did. It’s “my” router. I use the fios device as a modem only

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u/BearsBearsBears_wooo Aug 18 '26

Only if I connect to it with their wifi