AS2 messages are usually sent across the internet using the HTTP or HTTPS protocol. AS2 has been widely deployed as a point-to-point connectivity method between manufacturers and trading partners. AS2 offers many advantages over standard HTTP, including increased verification, and security achieved through the use of receipts and digital signatures. AS2 transactions and acknowledgements also occur in real-time, increasing the efficiency of document exchanges. Walmart was one of the first companies to help drive the adoption of AS2 across the retail sector.
File Transfer Protocol (FTP) is a standard network protocol used to exchange and manipulate files over a TCP/IP based network such as the internet. FTP is built on a client-server architecture and utilizes separate control and data connections between the client and server applications. FTP is also often used as an application component to automatically transfer files for internal functions within programs. FTP can be used with user-based password authentication or with anonymous user access.
Secure File Transfer Protocol (Secure FTP) is a network protocol that provides file access, file transfer and file management functionality over any reliable data stream. It was designed as an extension to the Secure Shell protocol (SSH) version 2.0 to provide secure file transfer capability, but it is also intended to be usable with other protocols as well. SFTP can be used in a number of different applications such as secure transfer over Transport Layer Security (TLS) and transfer of management information within VPN applications. This protocol assumes that it is run over a secure channel, such as SSH, that the server has already authenticated the client and that the identity of the client user is available to the protocol.