Here are all the modems for the ATT Samsung Galaxy Note i717. If you are on ICS, you can use any of the following modems. To flash them, boot into CWM recovery and flash this zip.
CWM recovery: hold both VOLUME UP and VOLUME DOWN and POWER. After you feel the first vibration, let go of the POWER button but keep holding the VOLUME UP and VOLUME DOWN.
For However, if you are still on Gingerbread, just use this modem.