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Ask Slashdot: AT&T's Data Usage Definition Proprietary?
stox writes "As many of you know, AT&T has implemented caps on DSL usage. When this was implemented, I started getting emails letting me know my usage as likely to exceed the cap. After consulting their Internet Usage web page, I felt the numbers just weren't right. With the help of Tomato on my router, I started measuring my usage, and ended up with numbers substantially below what AT&T was reporting on a day-to-day basis. Typically around 20-30% less. By the way, this usage is the sum of inbound and outbound. At this point, I decided to contact AT&T support to determine what exactly they were defining as usage, as their web pages never really define it. Boy, did I get a surprise. After several calls, they finally told me they consider the methodology by which they calculate bandwidth usage to be proprietary. Yes, you read that right; it's a secret. They left me with the option to contact their executive offices via snail mail. Email was not an option. So, I bring my questions to you, all-knowing Slashdotters: are there any laws that require AT&T to divulge how they are calculating data usage? Should I contact my state's commerce commission or the FCC to attempt to get an answer to this?"
You are looking at 2.5-5% overhead depending on TCP, UDP, frame size, etc. Not 20-30%. If you're feeling pungent, save up your bills for a year and file a small claims court action. Might cost you a few bucks and a couple hours. In exchange, ATT is 99% likely not so show up (therefore you win by default), or to call and offer you credit for cancellation. Should be worth a few hundred bucks to you.
DSL is based on ATM technology.
And ATM uses 53 Byte cells to transfer data. 48 Byte for the actual data and 5 Byte overhead to indicate things such as the destination.
Now when you want to transfer 50 Bytes of data, you need two atm-cells (vs 1 ethernet packet). This takes 106 Bytes of data on-the-wire.
When one end is measuring the Ethernet side (50 Bytes + ethernet overhead) and the other is measuring the ATM side you will end up with very different numbers.
I am no laywer and I am assuming the cap is part of your contract with them, I cannot see how they can keep their definition of bandwidth usage a secret. They are now basically claiming that you are restricted in your usage upto the cap but they refuse to tell you what the cap actually *means*. Without clear understanding of how usage is measured, the number of the cap is meaningless.
So you are subject to provions in a contract that you are not allowed to know. It would surprise me very much if they could hold that up in court...
Yep. And they do.
That's why I go elsewhere.
That being said, my mom used AT&T. They never got her bill right (always overcharged), and we had to call and they would correct it, but having to do that every month or two sucked. I told that to an AT&T solicitor at my door once, as to why I wasn't interested. Rather than defending his client and get a sale, he responded, with a dismayed and somewhat depressed, "wow... I heard about the same thing from someone just down the street," and moved to the next door. My mom doesn't know anyone on my street other than me, so it seems to me, overcharing is not an uncommon issue with them, and they are just trying to find more clever ways to hide it.
The author of TFS should verify that he's collecting headers, if so, he may have a case.
Self proclaimed typo king, and inventor of the bear destroying coffee table (patent not pending).
Unless someone is sending an awful lot of really small packets, the 40+ bytes of TCP/IP headers per packet are not going to add 20-30% to the data that is being sent. For example, the "Simple IMIX" as defined on WIkipedia has 58% of packets being 40 bytes long (they are common because they represent data acknowledgments with no data going in the other direction), probably significantly underweights the number of 1500-byte MTUs, and still only has ~12% TCP/IP overhead. It would be grossly inappropriate for AT&T to include any packet overhead beyond TCP/IP because any lower level overhead is an artifact of AT&T's network design that is outside the control of, and opaque to, the end user.
The availability of competing providers varies by market. There are parts of the US with NO broadband available at all, and others where there is only one carrier. Also, the whole issue here seems to be that the "terms" he accepted withheld relevant information - and that IS grounds for legal appeal.