The "Tether Police" Are Coming

They will just automatically give you the tether data plan for $45 a month if you continue to use 'free' tethering.
AT&T tells customers using unauthorized tethering methods to pay up or stop (update) -- Engadget

I might be wrong on this as it's been a while since I stuck my nose into how networks function but...
- either
It can be done by tracking MAC addresses. A MAC address is a completely individual 1 to 1 "physical" address that every device has. This info is typically hidden (contains no useful info about itself, ie. device type or location) and often ignored (since it's only useful to the sender and receiver), but does get sent out every time a device communicates with a network. Since AT&T can look into any aspect of their network traffic, seeing your device send out a data request with a MAC address not belonging to your phone is a dead giveaway.
- or
When entering tethering mode the phone informs the carriers. Be it by the nature of the design (possibly a requirement so other devices know they can connect to the phone) or an intentional choice by Google. There might be ways to work around this (if it is the case) by someone writing a custom programming that enables tethering while not changing the phones state (aka custom wifi modem), and/or modding the OS so it does not tell the carrier.

There are means of changing one MAC address, but not all hardware supports it. Plus you really can't have the end device and the connection point share MAC addresses because it is then IMPOSSIBLE for your phone to know if the incoming data is meant for it or someone it's servicing.

so they are going after android and iphone then? cause the article made it sound like it was only for the iphone ?

lotreaglesfan said:

so they are going after android and iphone then? cause the article made it sound like it was only for the iphone ?

Click to expand...

My understanding after reading a couple of articles is that they will go after ANYONE who tethers and pulls the extra data.

.....so much for my "unlimited" data plan....

What I don't understand about this whole tethering thing is "IT'S STILL TIED TO YOUR DATA PLAN".

I have the base 200mb/month plan - If I use all 200mb on tethering, than its my fault - Why should I have to pay AT&T for a feature that is built into the phone itself? I don't see the harm in using tethering whether I use all 200mb on a tethered computer or all 200mb on the phone. It still uses the same data package, righT?!?!

I don't use tethering personally, but I just simply don't see what all the fuss is about. It seems like AT&T is trying to charge people double for the data plan they already have!

FWIW - If they are tracking via MAC addresses, I would be willing to bet that there is a way with a custom ROM to mask (or even disable) MAC address reporting.

DaNaRkI said:

It can be done by tracking MAC addresses

Click to expand...

MAC addresses (in IPv4) aren't propagated past the first network device. So if you're using your phone as a Wireless AP, the connected device MACs won't be seen upstream (only the MAC of the NIC on the phone). Same as your home network: your MACs stop at your router (FYI, IPv6 works differently).

Also, while MACs are supposed to be unique, the industry doesn't have a guaranteed unique allocation across manufacturers, so there are dupes.

DaNaRkI said:

When entering tethering mode the phone informs the carriers.

Click to expand...

On stock ROM yes, on "aftermarket" no. Stock ROM just sends a message upstream and validates the tethering option on your service via something like the IMEI number of the phone.

3rd party ROM don't do this. That includes JB'ing on the iPhone.

I'm not 100% sure there's not something packet level that helps them ID it did/didn't originate from an "authorized" tethering app (or that something like that couldn't be implemented, though given time, could probably be spoofed).

If AT&T is going to attempt to ID tethering based on data usage, they'll spend a ton of time in court. Back around Christmas we were up in PA and I used my Captivate as a WAP, the wife and I both tethered our notebooks to it for ~1 week. She was on her MBP doing a little surfing, email, uploading photos, etc., and I was doing a little work, including accessing a couple of VPNs for some clients up in DC.

Across the whole week we used <400MB of data. Our usage for the whole month with still under 500MB. I have an "unlimited" plan that's been grandfathered the last couple of upgrades.

I see people post 2GB+ consumption via phone only usage all the time.

i.e., the data consumption can't (and shouldn't) be correlated to phone only vs. tethering.

I realize there's a contractual obligation, but this - like I said above - is going to lead to some legal issues. Especially if AT&T starts snooping data packets to try to analyze the content for signs of non-phone based client apps, etc.

Dante04SRT said:

What I don't understand about this whole tethering thing is "IT'S STILL TIED TO YOUR DATA PLAN".

I have the base 200mb/month plan - If I use all 200mb on tethering, than its my fault - Why should I have to pay AT&T for a feature that is built into the phone itself? I don't see the harm in using tethering whether I use all 200mb on a tethered computer or all 200mb on the phone. It still uses the same data package, righT?!?!

I don't use tethering personally, but I just simply don't see what all the fuss is about. It seems like AT&T is trying to charge people double for the data plan they already have!

Click to expand...

+1 here...I think ATTs solution should be to eliminate all unlimited plans...sorry about the grandfathering but they can do what they want...and give everybody 2GB and let us use it as we please. Over 2GB, charge whatever..$10/GB or something like that. That should be the end of it instead of all the BS their police tactics will cause

DaNaRkI said:

I might be wrong on this as it's been a while since I stuck my nose into how networks function but...
- either
It can be done by tracking MAC addresses. A MAC address is a completely individual 1 to 1 "physical" address that every device has. This info is typically hidden (contains no useful info about itself, ie. device type or location) and often ignored (since it's only useful to the sender and receiver), but does get sent out every time a device communicates with a network. Since AT&T can look into any aspect of their network traffic, seeing your device send out a data request with a MAC address not belonging to your phone is a dead giveaway.
- or
When entering tethering mode the phone informs the carriers. Be it by the nature of the design (possibly a requirement so other devices know they can connect to the phone) or an intentional choice by Google. There might be ways to work around this (if it is the case) by someone writing a custom programming that enables tethering while not changing the phones state (aka custom wifi modem), and/or modding the OS so it does not tell the carrier.

There are means of changing one MAC address, but not all hardware supports it. Plus you really can't have the end device and the connection point share MAC addresses because it is then IMPOSSIBLE for your phone to know if the incoming data is meant for it or someone it's servicing.

Click to expand...

I'm going to test this...I connected to mobile AP and waited until my laptop saw the AP. Then disconnected without using any data. We'll see if they can detect that somehow. I'm on stock 2.2

Look on the bright side guys, in UK by law 512 MB can be considered unlimited on a data plan.

fldude99 said:

I think ATTs solution should be to eliminate all unlimited plans...sorry about the grandfathering but they can do what they want...

Click to expand...

...wouldn't that void your contract?

Dante04SRT said:

What I don't understand about this whole tethering thing is "IT'S STILL TIED TO YOUR DATA PLAN".

Click to expand...

I meant to comment on this in my post above. I agree, and if we weren't talking about high data volume consuming smart phones, I might see it AT&T's way.

The problem is, we're talking about devices that can use email, web, photo/video hosting, social apps (with constant updates/notifications), GPS (downloading map data), plus steaming video & music, etc.

Add to that the ease of portability and battery life, we're talking about devices that can be used +constantly+.

Just let me purchase bandwidth and use it the way I want.

In the following thread
http://androidforums.com/t/300228-t-begin-charging-iphone-users-who-tether.html
I've made some arguments why tethering should be allowed with a data plan.

Once AT&T went to capped data they removed any legitimate reason to charge for tethering.

RedRyno said:

...wouldn't that void your contract?

Click to expand...

No idea...That is a question only an attorney could really answer with any accuracy

Sooo if its not about data but about the "right to tether", then I think ATT is heavyhanded. Mobile AP is something that is part of the 2.2 OS. Can they legally charge for a feature like that? Again, only an attorney or judge could truly answer that. But ATT won't stop attempting to take revenue from that feature unless it went as far as being pushed-most, including myself are either 1: too busy, or 2: too apathetic to actually do more than this bantering

fldude99 said:

But ATT won't stop attempting to take revenue from that feature

Click to expand...

The problem is that tethering is a completely made up feature. It costs them nothing to deliver. Yet they want to charge me for it.

Riddle me this.

Which of the following puts more stress on AT&T's network:
1. a 1 kilobyte packet transmitted from my phone to the nearest cell tower.
2. a 1 kilobyte packet transmitted from my phone to the nearest cell tower.

(Note that in the case of 1 the packet came from my mobile browser and in the case of 2 it came from my laptop connected to my phone.)


Which packet cost AT&T more money to route?

It's like the electric utility deciding they should charge you more for a kilowatt hour of electricity used for watching TV vs a kilowatt hour used for cooking. Even though both were delivered by the same wires.

It's like the water utility deciding they should charge you more for a gallon of water used for drinking vs a gallon of water used for washing dishes. Yet both cost them the same to deliver and came in by the same pipes.

Tethering is a completely artifical "feature". It's nothing. Vapor. Just a "feature" they made up so they can charge you for it.

DannyB said:

The problem is that tethering is a completely made up feature. It costs them nothing to deliver. Yet they want to charge me for it.

Riddle me this.

Which of the following puts more stress on AT&T's network:
1. a 1 kilobyte packet transmitted from my phone to the nearest cell tower.
2. a 1 kilobyte packet transmitted from my phone to the nearest cell tower.

(Note that in the case of 1 the packet came from my mobile browser and in the case of 2 it came from my laptop connected to my phone.)


Which packet cost AT&T more money to route?

It's like the electric utility deciding they should charge you more for a kilowatt hour of electricity used for watching TV vs a kilowatt hour used for cooking. Even though both were delivered by the same wires.

It's like the water utility deciding they should charge you more for a gallon of water used for drinking vs a gallon of water used for washing dishes. Yet both cost them the same to deliver and came in by the same pipes.

Tethering is a completely artifical "feature". It's nothing. Vapor. Just a "feature" they made up so they can charge you for it.

Click to expand...

My point exactly. All that other stuff mentioned in your post is good for conversation but really meaningless. If ATT can scare up revenue by charging for a native feature they will...right or wrong until pushed hard

That's one reason why public utilities are heavily regulated, I suppose.

Because they are monopolies and shouldn't be allowed to do anything they want to when there is only one electric utility in town.

The letter from AT&T makes it sound like USB tethering isn't allowed either.. Something that was built in to my phone and an automatic option every time I plug it in to a computer.

DataPro 4GB for Smartphone Tethering
&#8226; $45 per month
(this gives you 4GB in total, combining both your smartphone data plan for $25 and the tethering feature, $20)
&#8226; $10 per each additional GB thereafter, added automatically as needed
&#8226; Mobile Hotspot capabilities are included for compatible Smartphones

Click to expand...

The last line is what scares me... meaning the 25 dollar tethering charge is there even for phones without mobile hotspot capability.

What about apps like stumbleupon? When you stumble it takes you to a FULL webpage most of the time. They can't tell just by data if that full page came from my handset or my lappy tethered to my handset...

h4x0rj3ff said:

What about apps like stumbleupon? When you stumble it takes you to a FULL webpage most of the time. They can't tell just by data if that full page came from my handset or my lappy tethered to my handset...

Click to expand...

That is part of the question..that's not a given

read through the thread and i am still not 100% clear.

1) how can AT&T tell you are tethering? is it only by an increase in your data usage?

2) ok... they accuse you of illegally tethering... now what? they cant prove it can they?

what if i am a sexual deviant downloading porn all day? if i have an unlimited data plan i am allowed.

DannyB said:

The problem is that tethering is a completely made up feature. It costs them nothing to deliver. Yet they want to charge me for it.

Riddle me this.

Which of the following puts more stress on AT&T's network:
1. a 1 kilobyte packet transmitted from my phone to the nearest cell tower.
2. a 1 kilobyte packet transmitted from my phone to the nearest cell tower.

Click to expand...

Note that I don't agree with AT&T policy at all, but that's not how they're arguing it. Their claim is more about data volume across a fixed time period. i.e., how much concurrent bandwidth are you using (especially if the WAP allows multiple machines to connect).

See my discussion above about my thoughts on PC vs. Smartphone use.

sugarspunz said:

read through the thread and i am still not 100% clear.

1) how can AT&T tell you are tethering? is it only by an increase in your data usage?

2) ok... they accuse you of illegally tethering... now what? they cant prove it can they?

what if i am a sexual deviant downloading porn all day? if i have an unlimited data plan i am allowed.

Click to expand...

If you use the AT&T bundled tethering app, they can of course tell, and it won't work unless you pay. With 3rd party ROM, Jailbreak, etc., the app will no longer report to AT&T, it's simply a phone based WAP.

See my post above about data usage, that's a _dangerous_ path to pursue for AT&T.

If they accuse you, then I'd fire right back and make them indicate why they think you're tethering. If they say "data volume", then that won't stick (though like people have mentioned, it's tricky when you're bound to a private, contractual agreement).

I also believe there's no legal precedent that would allow them to snoop network packets and analyze for indicators/tokens that would prove a packet originated from a PC. Hell, if it's encrypted that's probably not even technically possible.