
Xfinity WiFi Home Hotspot FAQs - technel
http://www.comcast.com/wifi/neighborhood/faqs.htm?SCRedirect=true
======
georgecalm
Funny coincidence. I've just spent the last hour on the phone with Comcast
support asking them to disable the "xfinitywifi" my router is broadcasting and
when it was all over decided to unwind and read some NH... And see this!

For anyone who needs to, call "1-855-845-6834" and ask them to disable the
"xfinitywifi" hotspot on your router.

This will save you the 4 transfers, giving your info many times, and listening
to the upgrade options you don't care about. It may also save you from the $70
support they'll try to charge you (should you choose to agree), and possibly
one redirect to a number that no-longer exists (all of which I just went
through).

GL.

~~~
wmf
What's your objection to this feature?

~~~
georgecalm
First, there isn't enough technical info about how the feature is implemented
for me to not be worried about it affecting me in terms of security and
bandwidth; and from my subjective experience so far, I don't trust Comcast
enough to accept their claim of no / minimal impact.

Second, the way I see it, Comcast is asking us to donate our resources
(bandwidth, etc.), as minimal as they may be. Now, I don't mind donating to a
good cause. I do, on the other hand, mind being forced to do so, without my
consent; and especially so when a company is profiting from it ($3 daily
access pass for non-subscribers).

So, if (a) I could be sure that it will not affect me, and (b) this would be a
free for anyone who is in the area to use, and (c) they'd ask me to opt-in,
I'd enable it.

------
300bps
Essentially you have two WiFi networks in your house. What they call your
"private WiFi" network and the Xfinity WiFi network. The biggest question I
have is - do they both utilize the same publicly facing IP address?

This brings up some interesting questions. Consider 6 residents in an
apartment building, each with their own Comcast Internet connection. I utilize
my private network and the other 5 people for whatever strange reason chose to
connect to my Xfinity WiFi connection instead of their own connection. One of
them surfs for highly illegal content (take your pick). Whose door are the
police going to break down?

~~~
pliny
IIRC the MO for raiding nonviolent criminals is first to find and kill any
dogs in the residence, so it really just depends where the barking is coming
from.

~~~
maaku
So who's held legally liable for my dead dog?

~~~
protomyth
[http://reason.com/archives/2013/07/08/its-time-to-train-
offi...](http://reason.com/archives/2013/07/08/its-time-to-train-officers-not-
to-kill-d)

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smathieu
As far as security is concerned, I'm much more worried about ISPs providing
WiFi routers that uses WEP encryption AS A DEFAULT.

For those who don't know, WEP can be hacked in a matter of minutes with no
technical knowledge required. There's plenty on scripts on the internet that
automates the whole process for you.

Do yourself a favour and use WPA2.

~~~
ma_mazmaz
If you have FIOS, enabling WPA2 breaks their router, and tech support won't
help, claiming that WEP is "just as secure as a wired connection"

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kylebrown
This looks like a step toward what is variously called "hotspot 2.0" (Wi-Fi
Alliance)[1], "next generation hotspot" (Wireless Broadband Alliance)[2], and
"het-net" (4G Americas)[3].

The problem is the exponential growth in demand for cellular bandwidth. Its
very expensive for the cellular industry to increase capacity by building new
towers. So the idea is to get consumers' cellular devices using wifi data
connections wherever possible, offloading demand for 3G/4G.

This looks like a way for cell phone companies to lease an "xfinity password"
from Comcast. Then the cell company can seamlessly offload the data connection
of any subscriber near enough to an xfinity hotspot.

1\. [https://en.wikipedia.org/wiki/Wi-
Fi_Alliance](https://en.wikipedia.org/wiki/Wi-Fi_Alliance) 2\.
[https://en.wikipedia.org/wiki/Wireless_Broadband_Alliance](https://en.wikipedia.org/wiki/Wireless_Broadband_Alliance)
3\.
[https://en.wikipedia.org/wiki/4G_Americas](https://en.wikipedia.org/wiki/4G_Americas)

~~~
jessriedel
Interesting. Any idea why AT&T can't make their hotspots around nyc not suck?
I'd love to use them to save data, but I end up disabling my WiFi just to keep
my phone from auto-connecting and then not functioning.

~~~
voltagex_
On some versions of Android it is possible to set the system up to check for
the existence of a working Internet connection and then disconnect from wifi
if there isn't one.

~~~
jessriedel
Thanks for the tip. I think this is what you're talking about

[http://lifehacker.com/5802885/connection-checker-
disconnects...](http://lifehacker.com/5802885/connection-checker-disconnects-
you-from-crappy-wi+fi-and-3g-connections-for-battery-savings)

I'm going to try it out.

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HarrietJones
So does BT (In the UK) [http://www.btwifi.co.uk/](http://www.btwifi.co.uk/)

It's a good feature. The open wifi is separated from your wifi, and it doesn't
use your bandwidth. Plus - If you have BT wifi, you get to use all those
hotspots for free.

~~~
pktgen
I question "doesn't use your bandwidth." BT is a DSL provider. Your circuit is
provisioned for the speed you pay for, and the maximum attainable speed is
limited based on distance from the DSLAM as well as other factors (copper
gauge, copper condition, etc.).

If you're paying for the highest speed BT offers at your location and you're
near the limit for that speed, they don't have any capability to overprovision
a few extra mbps on that circuit for guest Wi-Fi use. The closest they can do
is provision a new circuit entirely, but that isn't a very cost-effective
solution just to provide Wi-Fi as it requires another physical pair, another
DSLAM port, and more expensive CPE that can support 2 pairs.

Comcast on the other hand is a cable provider and due to the shared
architecture of DOCSIS, can conceivably do that. In fact, since they're saying
guest Wi-Fi users will not impact your connection speed, I am betting that is
exactly what they are doing - guest Wi-Fi users probably have access to any
unused capacity on the node.

* maybe they have FTTP in some areas (like pretty much every telco) in which case this won't apply. And I know they have FTTC in many areas too, but that's still xDSL and these shortcomings still apply (just to a lesser extent since the loops are much shorter).

~~~
justincormack
Also you have to use their crappy router with DNS hijacking.

~~~
pktgen
Heh. Is there such a thing as a consumer ISP-supplied router that isn't a
total POS?

Does BT not let you override their DNS servers? I don't know why ISPs seem to
think DNS hijacking is such a good idea. I find it hard to believe they could
make any substantial amount of money on it, it just pisses people off.

~~~
cbhl
The average customer probably doesn't know what DNS is, let alone that
switching to a server that doesn't to DNS hijacking will make the <ISP> search
pages go away.

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bnchdrff
Taking a page from FON, it seems.

I'm curious how they do traffic shaping for the second network - does it
happen in router or upstream?

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tjdetwiler
Title is misleading. I interpret this as they broadcast a separate wifi signal
that connects to a different LAN. I don't see anything terribly wrong with
this.

~~~
eean
Yea this makes a lot of sense.

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rafeed
I was in the Bay Area a few weeks ago and was able to try out the Xfinity
WiFi. It was actually really convenient being able to work from the small
coffee shops in Berkeley and in the city. The speeds were awesome too, around
27Mbps down and 10Mbps up. Most places require you to pay for WiFi or the
speeds are just throttled way too much (1.5Mbps/0.5Mbps). As long as your own
service isn't being hindered by the Xfinity hotspot and your own network isn't
vulnerable due to the additional piggybacking, I don't see anything wrong with
it.

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beagle3
Does anyone who have this (or any of the other similar systems) know if you
the other people go out with your public IP or not?

If so, comcast/bt/bezeq has just killed all association between ip and
identity (not that there was much to begin with, but there was)

~~~
Swannie
In short, at BT, no way. Your IP is your LAN. Other users get different IPs.

BT runs three SSIDs. Your network, BT-Wifi (FKA OpenZone), and BT-FON.

Your network is your network. Private IP, different encryption. The packets
leave your house, travel over the ADSL, exit the DSLAM, into a BRAS. There
(more or less) it exits onto the "internet" connectivity of BT, with the IP of
your ADSL modem.

FON and BT-WiFi leave your house, travel over the ADSL, exit the DSLAM, into a
BRAS, but there's a difference now. Instead of exiting onto the "internet", it
is stuck in a channel that goes to a different part of the network. This part
hosts the server where you login/etc. and where your traffic eventually
leaves, with a different IP address than the home network, to the internet.
I'm fairly sure the IP is a proxy address, assigned to the logged in user's
session, and not tied to the specific router. That channel used to be 256kbps
reserved. I think it is now 512kbps. This channel has lower priority than your
normal internet traffic.

There is also another channel for BT Vision, that IIRC has 2Mbps reserved for
their video. I assume this never leaves the BT network for the internet :-)
This has a higher priority than your normal internet traffic (for obvious
reasons).

AFAIK the BRAS is where the quality of service is enforced. The router is
requesting the different classes of service though, and is tagging the
packets. (And I think it's also running a tunnel for the FON and BT WiFi).

EDIT: Corrected a mistake, added some clarity for other q's raised elsewhere.

~~~
voltagex_
It's interesting reading about a UK situation, the Australian industry is just
starting to take its first stumbling steps towards this:
[http://www.optus.com.au/network/mobile/homezone](http://www.optus.com.au/network/mobile/homezone)

The TV side of this can be found by searching TPG IPTV and FetchTV, but on the
whole we don't have enough bandwidth for this to be deployed successfully.

Where you say 2Mbps reserved, is this set up in the router as a separate
virtual circuit? In this case, does it make a hypothetical 20MBit connection
18MBit to the end user?

~~~
Swannie
Caveat: this is info based on a quick chat with a BT WiFi engineer, backed up
with random internet reading.

It's set up in the router and BRAS, but it will only take that bandwidth away
if you're watching IPTV. I should have used the word "allocated" :-)

Something important to note - even if you see sync speeds on your DSL modem of
34.95Mbit down, you're likely to have a DSLAM profile set to something like
31Mbit. Most providers use profiles in the DSLAM to give you a consistent
speed, rather than trying to squeeze the last little bits out of what is often
quite a lossy line.

So in reality your 20Mbit sync speed might result in an 18Mbit profile, of
which 2Mbit is allocated for IP TV traffic.

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godDLL
So does Bezeq (in Israel) [http://bezeq.co.il/](http://bezeq.co.il/)

They are trying to meet customer demand for wider bandwidth with VDSL, and
nearly stopped selling modems; it's all cheapo routers now, loaded with
customized firmware complete with DNS spoofing to route you to their "new
customer setup" page that seems to always be down. They have to be reset once
in a while, when their internals contort into reboot loops.

The free hotspot is branded and the name contains a short string unique to
your router. It might not be using "your" bandwidth with your ISP, but it is
sitting on your uplink which could get stuffed as a result. The hotspot is
completely open for anyone to connect, but is limited by the max_client
setting which is global to the router and set at 16 clients by default.

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moskie
I have Comcast, with one of their wireless routers, but I don't see any
network named "xfinitywifi." Is it only certain router models? Or only certain
areas?

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metavida
From the "How can visitors connect?" page:

> Visitors who are XFINITY Internet subscribers can simply select the XFINITY
> WiFi network “xfinitywifi” on their device and open a Web browser to get
> started. They will be able to sign in with their XFINITY email or username
> and password.

So now anyone can create a hotspot named "xfinitywifi" and phish for passwords
from folks who doesn't look for an https connection. I hope Comcast does some
good training beyond "connect and enter your password."

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Havoc
Oh I'd disable that so fast. It'll mess up gaming latency in a heartbeat.

~~~
ars
No it wouldn't. It's a separate WiFi device, using a separate allocation of
bandwidth. How would it have any effect?

~~~
Havoc
It will affect the latency on the actual internet link. The second you add
extra traffic latency shoots up...it doesn't matter where that traffic comes
from. You can mitigate the effect somewhat with QoS but it doesn't go away.

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seanalltogether
How do features like this affect wifi congestion in the long run? I have 14
wifi networks at near full strength visible from my home office already.

~~~
hmottestad
The issue isn't the number of networks, but rather the number of frequencies
used.

The second ssid being broadcast will probably run on the same frequency as
your usual ssid.

Switching to super high frequencies will mitigate the overlap, since these
won't travel through thick walls, but then you may need to put wifi points in
all you rooms.

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LarryMade2
I've used it, my local network connection was down and I found there was a
wireless Comcast hotspot available.

I figured that was the case (Comcast wifi piggybacking on someones
business/residential connection) but wasn't sure. It's not from me as I'm
using my own modem and router.

There's a an interactive wi-fi location map on the Comcast page that shows
where hotspots are, two are in town so far.

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pvns
So does Portugal Telecom (in Portugal), at least in its triple-/quad-play
services, locally known as MEO and M4O packages. Those who enable this sharing
service (called "community hotspot") can also benefit from it. I believe it
started out as a response to the competition giving their clients access to
the (global?) Fon WiFi network.

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officialjunk
Is this only if I use a comcast wireless router? I use a Comcast cable modem
and then my own configured wireless router. Does this apply to me too?

~~~
nightpool
Do you have an XFINITY Wireless Gateway? Can you see an addition xfinitywifi
network?

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nekitamo
I have an Xfinity Wireless Gateway, and I see no visible networks named
"xfinitywifi" nearby.

~~~
voltagex_
Yet. Don't these have automatic firmware updates forced down from Comcast?

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infocollector
Comcast = ?

~~~
prawks
Cable provider in the US.

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escaped_hn
I wonder if you can use Cain and Able and log everything from that signal
using arp poisoning.

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freeasinfree
These things are a nuisance to spectrum.

