Comcast is turning your Xfinity router into a public Wi-Fi hotspot | Hacker News Reader

Comcast is turning your Xfinity router into a public Wi-Fi hotspot

blog.chron.com

37 pointsweef56 comments

I hate big cable companies as much as the next person, but I really don't have a problem with this as long as a few things are in place:

1) Network isolation, according to the article there is some isolation. Not sure what this means exactly but if it's a private subnet routed to Comcast on a separate IP for security/privacy reasons. There is no technical reason this can't be accomplished. I do question how much Comcast (or their vendor) engineers care about security though.

2) Doesn't affect my speed, article states this. Assuming it's true, modern DOCSIS 3.0 cable modem can support an absurd amount of traffic, way more then most WiFi APs can handle at any reasonable range.

My biggest concern is that WiFi is already slow, if I'm streaming Netflix videos and it now starts to drop segments due to a person in a car on a tablet streaming the latest Gangnam style, I'll be upset.

Network isolation would be my biggest concern if I had to deal with this. However, since I long ago got rid of Comcast's cable modem and installed my own, and have always had my own wifi router plugged into it, I thankfully don't have to worry about it.

This is simply PR BS without a separate IP:

"Kurn said no, anymore than Starbucks is liable for illicit behavior by the customers who use its in-store hotspots."

The separate IP is the key here when it comes to network isolation. If there is no separate IP, the customer will be held liable for illegal use, despite Comcast's ridiculous denial. Starbucks doesn't have to worry about being sued or prosecuted for the crimes of its customers because it has plenty of billions to defend itself. Joe Smo, your average end user who probably hasn't read the mail or e-mail about this and has no clue that it's on, should worry as he would be a target for other corporations lawsuits and even criminal prosecution. Without a separate IP and separate audit, he's going to get sued or thrown into jail. The authorities don't look kindly on such things as kiddy porn and won't care that it was some stranger using your wifi from across the street.

I hate Comcast. But I like this. FREE (french provider) has been doing so for years now. You router shares a second speed-limited connection which doesn't slow down your own speed, and other Comcast members can connect to it with their pass.

Maybe it's bad practices to not tell the customer or whatever, but now in Paris, if you are a FREE customer, there is literally WIFI everywhere for you. And it's amazing.

just my 2cents :)

Orange.fr has been doing the same for a while. This is a newer article but in southern france Orange were doing it in 2012 when I lived there.

http://www.muniwireless.com/2013/06/10/orange-france-creates...

Also my experience with 'free' was that it's vaporware. Hopefully it's improved in the last 1.5 years.

The article states that there is separate bandwidth allocated to the public wifi. I wonder if there is a way to bridge the two together? Say wired into your own and wireless into the public and get twice the bang for your buck.

Comcast is more than willing to allow you to have your own cable modem and will even assist you in setting it up. I did this recently when I drop phone service they were providing and no longer needed their special modem. So seven dollars a month charged for it became zero with my spending less than eighty dollars and ten minutes on the phone with their tech support.

My concern with their plan besides being opt-out is, who is liable for misuse of the signal?

The wifi requires you log in with a Comcast user ID and password. It's not an open wifi network, and only paying Comcast customers have access to it.

Not true if you have static IPs. For that, they require you to use their modem, even though many CSRs will tell you otherwise. I bought two modems, on the advice of CSRs, and when I tried to activate them I was told I couldn't. Only after the second, was I told the real reason. (For the first, I was told the modem was the wrong model and the CSR I spoke with gave me incorrect information.)

This is quite scary. "by default, the feature is being turned on without its subscribers’ prior consent. It’s an opt-out system".

There's not really anything to worry about. One of the UK's largest ISPs, BT Broadband, does the same kind of thing (in collaboration with their own network of 'BT Openzone' public wifi spots, and the 'Fon' network).

Basically, (unless an individual subscriber has chosen to disable the function) their home router radiates a second Wireless SSID, which is _completely_ isolated from your connection (all traffic to/from is tunnelled over a VPN back to ISP base) and _never_ detracts from your download speed (your own traffic always takes priority.)

In return, you have wireless access to thousands of similar hotspots - and in any populated area there's a more than reasonable chance that you'll be near someone that uses BT broadband. (UK's largest ISP.)

Nothing not to like about it. It's really convenient and works well.

That's under the assumption that those who write & test the code for those Comcast devices is competent.

So, setup your own router, call it "xfinitywifi" and collect Comcast login information all day?

I wonder how much a hacker could hurt Comcast's bottom line by setting up troll-hotspots, getting people's Comcast info, and then use the info to call in and cancel accounts. I bet someone working hard could clear $1k/mo of accounts each day in a couple hours.

Not to mention all the fun data leakage that happens when using open wifi portals.

Here, a little hand with that -

http://www.offensive-security.com/kali-linux/kali-linux-evil...

Kali Linux Evil Wireless Access Point

Comcast is pretty solid. I know it tends to get a lot of hate but my experience has been fairly consistent.

Like some others have said, as long as it doesn't screw around with my own connection, then it's not a big deal. Plus I'll now be able to access internet in a lot more places that didn't have free Wi-Fi before. It's really useful for me since I only have a 200mb data plan.

With all the hate that is going around right now for ISPs, it amazes me that they would roll something out like this.

At least they let customers to opt-out. In Malta (EU) there is an ISP called Melita - pretty much a monopoly - which enforced similar to all it's customers without even informing them and without letting them to turn it off.

It's an outrageous practice to enable radio-emitting devices in customer's homes without their consent. Unfortunately, they didn't see any backlash from the customer base, as most didn't understand what happened and believed to what lies ISP published on their FAQ page - that additional WiFi spot doesn't emit extra EMF and doesn't consume extra electicity...

I had to go to the lengths of reversing modem firmware looking for exploits in order to disable this.

I wonder if you could simply wrap the modem in an aluminum foil (provided that you have your own router connected to it).

I just unscrew the little aerial when I use a wired connection (we don't have the public wifi rebroadcast thingy yet)

Looking for exploit was fun - found provisioned administrator password to access any modem on the WAN - but yes, unscrewing antenna is the first idea which comes to mind.

If it mattered to me that much I'd take it apart and unsolder the antenna then re-assemble and deny all knowledge.

Unless I owned the equipment then I'd just cut them off.

Good thing I bought and use my own router and modem. Although the interesting bit I noticed from the article was about the 'additional bandwidth' that gets allotted. Meaning Comcast doesn't let you use all of your bandwidth.

DOCSIS 3.0 modems support at least 171 Mbit/s https://en.wikipedia.org/wiki/DOCSIS#Speed_tables But you have to share those channels with your neighbors, and then you have to share the back-haul lines with lots of people. So no, you don't get to use all the available bandwidth, but I don't think Comcast ever pretended that they weren't limiting you. If you upgrade to faster service they just click a button to bump your allotted speed up.

Wait. So a single DOCSIS 3.0 modem (which I own) can support 171 Mbit/s but Comcast gives me 50 for the low price of $70/month (not including TV)?

The modem can, but that doesn't mean the cabling, or the cable plant on the other end can.

I work for a telco, we just upgraded all our cable and plant for 13k customers so we could offer 100Mbit down / 10Mbit up. The old max speed was 50/5. The cost was in the millions, even though the modems have supported it for years.

So roughly $76 per customer. That cost could be amortized over, yknow, 6 months at $12.

edit: You did say, "millions", but my point still stands. Unless it was 10+ million, which seems like a stretch.

also: You don't have to amortize it over anyone in particular. You have revenue, you get to dictate how that revenue is spent.

It was a few "millions".

Remember, too, that only a small percentage of customers have chosen to upgrade to 100MBit, so you can only amortize it over them. We did the business case beforehand and it didn't really make sense to be honest. We did it to keep the regulator happy(er) (we're not in the US).

Yes, but how bad would you feel if you had been promised 171Mbps for a higher price and you only really attained 70-90 because you had to share the bandwidth with your neighbors? In your case, they could probably offer more than 50MBps, but they're playing it safe with 50MBps.

It makes a lot more sense to evaluate an ISP based on the speed and latency they give you for the price (along with other factors like service, reliability, ethics, etc.), not how much of your modem's theoretical maximum bandwidth they're able to use.

In order to be DOCSIS 3.0 certified, your modem does have to support 4x4 bonded channels (4 channels up, 4 channels down). But that does not mean your provider has the channels available or will provision them for you. DOCSIS 3.0 modems will happily provision themselves down to 1 6.5Mhz channel down, yielding just 38Mbits as a maximum.

There's a lot more to it than just channel allocation, as well - the 38Mbit maximum for a 6.5Mhz channel is with 256QAM and a good signal-to-noise ratio, which depends on a huge variety of factors.

Plus, even if you're getting plenty of channels allocated and have a good SNR, there's still the backhaul from your nearest point of presence into Comcast's WAN, the bandwidth across Comcast's WAN, and then whatever peering agreements they have to get across to the Internet at large.

At any rate, I think this is a pretty silly argument against Comcast - it's like being angry that your Gigabit Ethernet switch doesn't give you 1000MBit access to some random server on the Internet.

Unfortunately here in Louisville/Boulder Colorado, it's either Comcast or Century Link. I have tried both and done my own testing, and Comcast is still the best connection despite their price point.

I could not agree more about latency. My first try with Century Link last year had 120ms latency which is terrible because Comcast was 15ms. CL upgraded my neighborhood loop and got to 20ms which is fine, but the CL upload speed is still crippled at an outdated 768kb/s where as Comcast I get 3.5Mb/s upload. I work from a home office so upload bandwidth is important.

So since there is no other contender that has both good latency and upload speed I use Comcast for now.

I hate Comcast as much as the next guy, but at least here in Chicago, they're very expensive and very good. I hate dealing with them, but paying $90/mo for 105/20 that works well is better than paying $60/mo for something that doesn't (RCN).

Comcasts "bandwidth" is a shared pipe that includes your neighbors internet and a your TV channels. The vast majority of that bandwidth has never been dedicated to your private use.

This sounds shady to me i mean if you're a customer paying for a top tire internet connection that uses all the data capacity you line can give you how is it not affecting you when this starts serving other people?

The line must be able to handle more bandwidth but somehow i doubt ISP's had the foresight to leave some extra for just this occasion.

Is the router even capable of handling the extra load this would introduce? Most consumer routers are known for being under powered.

> This sounds shady to me i mean if you're a customer paying for a top tire internet connection that uses all the data capacity you line can give you how is it not affecting you when this starts serving other people?

They probably don't provide such a service; few cable operators use the maximum possible bandwidth on DOCSIS3.

Most people don't run their connection at full capacity all the time. It's easy to conceive of a router that devotes unused bandwidth to public wifi but gives it low priority compared to requests from the lessor's wifi network. It's not like you have a router and are on the same wifi network as the people walking by in the street.

DOCSIS 3.0 modems are capable of 40 Mbit per channel, and the Arris Modems comcast is doing this with has 8 downstream channels (320Mbit) and 4 upstream channels (160mbit.)

They've been doing this -- at least here in Philadelphia -- for quite some time now. The idea is nice, I suppose: it's nice to be able to walk around the city and have a wifi signal in most places. But the reality is, the connection is almost always so poor it almost never makes connecting worth my while, because it actually results in a POORER experience.

And what about those jurisdictions where you are responsible for file sharing that occurs on your network?

It's not your network. It's Comcast's.

Sounds like they require customers to log in with their Comcast credentials. My understanding is that in the US, the laws are such that if someone is authenticated into a wifi system, the provider of the wifi network is no longer liable. The article alludes to this in the closing paragraphs.

British Telecom has been doing this for quite a few years now as "BT FON".

I have to say as a visitor to London last year I was pretty happy being able to get wifi all over the place without using my phones data plan.

That being said I'm also happy I bought my own cable modem for my comcast internet service.

Solution: hack it, upside-down-ternet style: http://www.ex-parrot.com/pete/upside-down-ternet.html

This has been in place in San Francisco for quite some time (at least a year, I believe, if not longer).

It seems like a great idea...for opening a giant MITM attack vector to anyone who chooses to use it.

I can login and connect to the xfinity wifi at home but, it never works when I try it at a public place. It seems like just another service they advertise but, does not work.

Just tried to opt-out. Took about 20 minutes because "something is wrong, please try again later", rinse, repeat.

Finally I was able to do it, but now the page where you opt-in/out won't load so I can't confirm (and of course my neighbors all have it enabled so I can't tell if the network is mine or not).

Shameful but totally expected. ANY option for high speed internet would be better than this (except every other cable provider as they're all just as bad).

I suspect this will have a major impact on file sharing lawsuits where your IP is used to identify you.

I suspect(hope) that they will have a separate IP for this.

My understanding is that users use their Comcast credentials to login to public wifi.

I hope they'll use IPv6 for this.

I imagine IPv4 connections will use CGN or similar...

It won't because (at least in the UK model), other people using the public hotspot have their traffic tunnelled over a VPN back to the ISP. They don't share your IP address and their traffic is clearly and accountably separated from your own personal Internet use.

Sure, some big companies are stupid, but not THAT stupid.

What I want to know is if this will count toward my 300gb data cap.

You could at least have read a sentence or two of the article if you really wanted to know.

Separate network, requires Comcast credentials, has -zero- to do with your account/data cap - other than sharing your Wifi.

Sorry but all I read was 'separate from home network'. I don't see any mention of the data caps in that article. Though I could very well be blind.

I had to go to the xfinity FAQ to find the answer. http://wifi.comcast.com/faqs.html

And 2.4 GHz continues to go to shit with 5 GHz close behind. It's bad enough I can't turn off the WiFi on my own (rented) modem without having to call someone and go through the rigmarole, now there's a second network to deal with.

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