AT&T* M2X* IoT initial signup
1. Create an account on https://m2x.att.com, if you do not yet have one. If you already have an account, you can skip directly to "Adding your first device" below.
2. Fill out your information when signing up.
3. Verify your email address by clicking the link in the email received by AT&T*. (Be sure to check your spam folder, the verification is required to continue.)
For more such intel IoT resources and tools from Intel, please visit the Intel® Developer Zone
Source: https://software.intel.com/en-us/articles/connecting-to-att-m2x-iot-using-mqtt