AS1 EDI over the Internet (EDI/INT) is a working group of the Internet Engineering Task Force (IETF), chartered with creating specifications for transporting EDI or XML documents over the Internet in a secure (digitally signed and encrypted), highly reliable manner. Applicability Statement 1 (AS1) and Applicability Statement 2 (AS2) are industry standards for Internet-based data exchange. When you choose an AS1 or AS2 certified solution, you'll be able to exchange data with any trading partner using an AS1/AS2 interoperable solution via the Internet. Standards such as AS1 and AS2 simplify communication by reducing the number of technologies an organization must support and manage. If every large organization used a different data transport standard, it would be cost-prohibitive for their smaller business partners to exchange data with them electronically. AS1 and AS2 allow organizations to implement one solution for data exchange with all business partners who are using an AS1 or AS2 solution.
AS1: Secures data with S/MIME (Secure/Multipurpose Internet Mail Extensions) encryption over SMTP (Simple Mail Transfer Protocol). AS1 uses MDN (Message Disposition Notification) for proof of receipt. AS2: Secures data with S/MIME over HTTP (Hypertext Transfer Protocol) or HTTP/S (HTTP secure), also using MDN. Unlike AS1, AS2 provides synchronous, real-time transmission of data with immediate message delivery notice.
How does AS1 compare with AS2? Organizations benefit by greatly reducing the cost associated with traditional, Value-Added Network (VAN) EDI with either AS1 or AS2. AS1 uses SMTP to provide asynchronous, "store and forward" data transport, whereas AS2 makes use of HTTP protocol to allow for much faster synchronous, "real time" transmission of data with immediate message delivery notices. How AS1 Works AS1 and AS2 are the current specifications developed by the IETF for transporting data between organizations via the Internet. AS1 secures data with S/MIME (Secure/Multipurpose Internet Mail Extensions) encryption over SMTP (Simple Mail Transfer Protocol) using MDN (Message Disposition Notification) for proof of receipt. This graphic shows how AS1 works in a typical data exchange between two trading partners. 
