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AT&T trying to crackdown on unauth. tethering

arstechnica.com

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Re: AT&T trying to crackdown on unauth. tethering

#2

Post by paylesworth »

I'm curious to find out what you guys / gals think about this. Is this just a fear tactic? Or, does ATT have a legit way to check if you're doing unauthorized tethering. Any of you get hit with this text on accident (false positive)?

EDIT Removed the '(Ars)' from the title. N00b mistake :)

Re: AT&T trying to crackdown on unauth. tethering

#3

Post by weaksauce »

paylesworth wrote: post #2

I'm curious to find out what you guys / gals think about this. Is this just a fear tactic? Or, does ATT have a legit way to check if you're doing unauthorized tethering. Any of you get hit with this text on accident (false positive)? EDIT Removed the '(Ars)' from the title. N00b mistake :)

They probably just see that you are using more bandwidth than a normal user and infer that way. If they were packet sniffing your non phone traffic they might be able to infer from a plethora of non phone headers that the system will invariably send out. (system update check in the background. Etc. )

Re: AT&T trying to crackdown on unauth. tethering

#4

Post by dpritchett »

paylesworth wrote: post #2

I'm curious to find out what you guys / gals think about this. Is this just a fear tactic? Or, does ATT have a legit way to check if you're doing unauthorized tethering. Any of you get hit with this text on accident (false positive)? EDIT Removed the '(Ars)' from the title. N00b mistake :)

Supposedly all packets from the iPhone have a TTL of 64; packets from your laptop routed through the iPhone would not necessarily have the same TTL and are thus detectable.

[1] http://www.reddit.com/r/technology/comments/g62wv/i_woke_up_...

Re: AT&T trying to crackdown on unauth. tethering

#5

Post by gte910h »

paylesworth wrote: post #2

I'm curious to find out what you guys / gals think about this. Is this just a fear tactic? Or, does ATT have a legit way to check if you're doing unauthorized tethering. Any of you get hit with this text on accident (false positive)? EDIT Removed the '(Ars)' from the title. N00b mistake :)

There are dozens of legit ways to automatically detect this, and dozens more if humans are involved.

Requesting non-mobile versions of sites that do not have the option

User Agent strings such as "Internet Explorer" or "Safari" in HTTP requests

Sending screen sizes via relatively common web calls

The use of UA-Pixels at all, especially when specifying large screen sizes.

Use of protocols that are only seen in desktop OS programs (ventrilo, starcraft2, etc for instance is one that should be a good detector).

Re: AT&T trying to crackdown on unauth. tethering

#6

Post by eekfuh »

gte910h wrote: post #5
paylesworth wrote: post #2

I'm curious to find out what you guys / gals think about this. Is this just a fear tactic? Or, does ATT have a legit way to check if you're doing unauthorized tethering. Any of you get hit with this text on accident (false positive)? EDIT Removed the '(Ars)' from the title. N00b mistake :)

There are dozens of legit ways to automatically detect this, and dozens more if humans are involved. Requesting non-mobile versions of sites that do not have the option User Agent strings such as "Internet Explorer" or "Safari" in HTTP requests Sending screen sizes via relatively common web calls The use of UA-Pixels at all, especially when specifying large screen sizes. Use of protocols that are only seen in desktop…

There are 3rd party web browsers on the appstore and though would trigger false-positives, so they probably would't use UA.

Re: AT&T trying to crackdown on unauth. tethering

#7

Post by mattmanser »

gte910h wrote: post #5
paylesworth wrote: post #2

I'm curious to find out what you guys / gals think about this. Is this just a fear tactic? Or, does ATT have a legit way to check if you're doing unauthorized tethering. Any of you get hit with this text on accident (false positive)? EDIT Removed the '(Ars)' from the title. N00b mistake :)

There are dozens of legit ways to automatically detect this, and dozens more if humans are involved. Requesting non-mobile versions of sites that do not have the option User Agent strings such as "Internet Explorer" or "Safari" in HTTP requests Sending screen sizes via relatively common web calls The use of UA-Pixels at all, especially when specifying large screen sizes. Use of protocols that are only seen in desktop…

How are any of these legit, all of that's illegal wiretapping.

Re: AT&T trying to crackdown on unauth. tethering

#9

Post by bcrawford »

paylesworth wrote: post #2

I'm curious to find out what you guys / gals think about this. Is this just a fear tactic? Or, does ATT have a legit way to check if you're doing unauthorized tethering. Any of you get hit with this text on accident (false positive)? EDIT Removed the '(Ars)' from the title. N00b mistake :)

It is possible for them to detect this if they are doing Layer 7 inspection. All it would take is parsing the user agent to see that you're not on Mobile Safari. On the iPhone side, it just does a NAT and theoretically passes all information as the public IP of the phone itself.

Honestly, any respectable nerd is going to have either a) a box to SSH to or b) a VPN endpoint... if you encrypt/encapsulate all traffic originating from your tethered machine there's very little chance they'd be able to catch you.

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