FURTHERMORE, UNLIMITED PLANS (EXCEPT FOR DATACONNECT AND BLACKBERRY TETHERED) CANNOT BE USED FOR ANY APPLICATIONS THAT TETHER THE DEVICE (THROUGH USE OF, INCLUDING WITHOUT LIMITATION, CONNECTION KITS, OTHER PHONE/PDA-TO-COMPUTER ACCESSORIES, BLUETOOTH® OR ANY OTHER WIRELESS TECHNOLOGY) TO LAPTOPS, PCS, OR OTHER EQUIPMENT FOR ANY PURPOSE.

It seems in the UK we were screwed for years with high broadband prices etc, but it seems AT&T are screwing the US charging $30 just for tethering!?

In the UK the likes of T-mobile have unlimited web and walk for £7 odd, even the pricier O2 are going similar things now. If they tried to charge extra for tethering I’m sure people would jump ship.

As packetwerks pointed out how could they actually check it was tethered / direct from the iphone. The obvious thing would be the useragent of the browser but that can be spoofed easily enough

To Anders Fredriksson: your kidding right? It’s AT&T’s network. It’s always their business. You’re paying for the privilege to use it and you have to play by their rules….which doesn’t include tethering if you’re not paying extra for it.

Amazingly stupid.

1. This is a HTTP SOCKS proxy. That means that it will NOT forward the following protocols:

* DNS
* VPN traffic
* IRC
* SMTP/IMAP/POP3
* and so on…

I use NetShare and jailbroken apps to “tether” my laptop. I use “tether” loosely. It works great with Adium, Firefox, Twitter apps, and pretty much any app that uses HTTP AND (this is key) doesn’t rely on DNS resolution to resolve names. For example, in Firefox you need to edit about:config so firefox dumps DNS resolution off to the proxy, rather than your laptop’s defined DNS server(s). There are instructions for doing this out there. Use a well-known search engine to find them.

2. I am going to go out on a limb and say that AT&T has no easy way of telling if you are tethered. Here is why: It’s all IP traffic. How does AT&T know if the request came from your laptop or from your iPhone? They would have to do deep packet inspection, see that you are using a Mozilla User-Agent, etc. Since the packets are originating from your iPhone’s IP stack, even traditional methods to passively identify the device generating the traffic (e.g. TTLs) won’t work.

The easiest way to see that someone is tethered would be if they saw a ton of bittorrent, ssh, etc. traffic. Even if I moved 1GB of HTTP in a day, who’s to say that I wasn’t just using Pandora, Youtube, etc. I would make a wild ass guess and say that 95% of iPhone user’s traffic is port 80/443.

3. I have no legal experience and am not a lawyer. That said, I don’t think that using this app is against the letter of AT&T’s TOS. When I use this app, I am not tethering my laptop to the handset. This app is a PROXY server not a routed NAT application. The IP stack that is connected to AT&T’s network is still the iPhone’s. When I use an AT&T aircard or tether my old crappy 8525 on my laptop, that is different as my laptop is DIRECTLY connected to AT&T’s IP network. The snarky lawyer in me would argue that my laptop is merely asking the locally connected iPhone app to fetch something off the internet for me. It returns it to the iPhone, processes it in iPhone memory, then passes it to my laptop. I am just using an Apple-approved iPhone app that just happens to be controlled by my laptop. I rest my case.

4. Again having no legal experience, I don’t think that this app is against the spirit of AT&T’s TOS. Here is why. AT&T’s network engineering (this is key) folks don’t want laptop users to pull massive amounts of IP traffic over their network. It is the same issue that home ISPs are facing more or less. That said, if I visit http://www.espn.com from my Firefox and from my iPhone’s Safari, what is the difference? Maybe the total traffic downloaded via Firefox and iPhone Safari is 2MB. What is the difference? If I watch the same Youtube video in Firefox or Safari, what is the difference? The iPhone’s IP traffic “footprint” for HTTP traffic is nearly identical for most users using most HTTP-based applications.

Lest we forget that AT&T is a phone company with investors and employees to pay. The reason why they don’t want you to use this app is that AT&T sells laptop connect cards that mean $60/month revenue for them.

5. If you are really worried about getting caught by AT&T, use a Cisco IPSEC VPN to tunnel all your laptop’s traffic. The iPhone has a built-in VPN client. AT&T a.) Won’t be able to see what you are doing, b.) Won’t be able to tell if you are tethered or using the phone’s VPN client.

If I was AT&T I would make a bad-ass tethering app that does true routed NAT and charge users a nice monthly fee. Business users would eat this up without thinking and I think you’d see a ton of people signing up for unlimited “tether” plans.

6. Someone out there is going to port slirp (old school PPP hack) which will allow 100% tethering. The hacker community already did this for the last iPhone. What is going to ruin all of this is that the kids are going to fire up Torrents and AT&T will have a cow and start cracking down. Mark my words, you will see the headline “AT&T Blocks/Throttles Torrents for iPhone users” very soon.