That sounds about right. Because if you had read the entire thread you would've noticed that I went from a 100FT phone line to a 25FT phone line. After running a speed test the only difference was our Internet speed increasing by 2 Kbps.
Judging by your speed test you don't have any problems.
Your advertised speed is in kilobits per second. 768 kbps to be exact. That's where your modem is capped at.
The way how DSL works, you have certain overhead. Usually ATM + PPoE + TCP/IP. With PPPoE your combined overhead would be about 15%. Without about 13%, so max data transfer (payload) would be about 87% in best case.
The speed shown on your speed test is pure data throughput without overhead.
Your result shows 670 kilobits per second, which is slightly over 87% of your advertised 768 kilobits per second.
That means your connection is nearly perfect.
As for "83.8 KB/sec transfer rate", that's your speed in kilo
bytes. 1 byte is 8 bits. 670 / 8 = 83.75 or 83.8
KB=kilobyte
kb = kilobit
You don't have any problems. Don't bug AT&T support. Let them use that time to help people who really need support.