One of the most critical aspects of transforming the nation's public safety answering points (PSAPs) from today's legacy 911 technology to Next Generation 911 (NG911) is adherence to a common set of standards. Development and adoption of international standards is key to achieving 911 interoperability across multiple local, regional, state, and national public safety jurisdictions, and beyond into the global emergency communications environment. Based on conceptual definitions dating from 2000, development began on NG911 standards in 2003 when the National Emergency Number Association (NENA) initiated technical requirements and definition work on core Internet Protocol (IP) functionality and architecture. Beyond the walls of the 911 PSAPs, the consistent observance of standards is essential in accomplishing seamless transmission of data from the caller to 911, and on to emergency responders.