You shouldn't use your TomTom login/password as your cellular network login/password. They are two separate things.
The phone company known as "CellularOne/AT&T Wireless Services/Cingular/AT&T Mobile" has at least two access settings that they have inherited over the years. I looked online, compiled information together from different sources, and came up with this:
WAP (should be more friendly towards GPRS):
Access point name = wap.cingular
Username =
WAP@CINGULARGPRS.COM
Password = CINGULAR1
IP = Automatic
DNS = Automatic
Dial number = *99***1#
Login script = AT+CGDCONT=1,"IP","WAP.CINGULAR" (CGDCONT are letters, not the number 0)
ISP (should be more friendly towards EDGE and/or tethering):
Access point name = isp.cingular
Username =
WIXDC001@W5.MYCINGULAR.COM (001 are numbers, not the letters O and I)
Password = ZXY203DCPK0402 (203 and 0402 are numbers, not the letter O)
IP = Automatic
DNS = Automatic
Dial number = *99***1# (some reports of using 3# instead of 1# to achieve higher speeds if you are using EDGE)
Login script = AT+CGDCONT=1,"IP","ISP.CINGULAR" (CGDCONT are letters, not the number 0)
Note that entering the login script with the TomTom's onscreen keyboard is an exercise in patience and nerves! The "OK" button is dangerously close to some of the other keys you will need to be hitting....
I have only WAP, not ISP. The WAP settings are known-good working on my phone (Palm Treo 680). Unfortunately, I haven't yet gotten it to work with my TomTom 930.
I noticed that some of the settings are different from the defaults that are in the TomTom. Among other things, the dialup number is different, and the login script has slightly different case in some of the parts of its command. Has anybody ever successfully used these to connect with?