Area code and exchange code is assigned to every constituent of city in the United States. The area and exchange codes of the telephone can be used to find information about a region. Area code 682 and exchange code 831 is assigned to Roanoke. The latitude and longitude corresponding to 32.99 and -97.23 can be used to find an area on the map. Southwestern Bell - Txoperates most of the land lines in United States.