Instantly talk across the largest Push to Talk network in America with the push of a button. Enjoy all of the extra features that come with AT&T Push to Talk, such as Quick Groups, Call Waiting and Availability Status. Push to Talk service is not available while roaming outside the United States. Customers subscribed to a Nation with Canada or Vive Mexico rate plan will not be able to utilize Push to Talk service while roaming in Canada or Mexico even though regular GSM voice service is available there.