AS1-HISTORIC
AS1 historical context. See official source.
Definition
Historical perspective on AS1 (RFC 3335, September 2002) — first Applicability Statement in the IETF EDIINT series, based on SMTP and S/MIME.
Origin
Born from joint IETF EDIINT and CommerceNet work, AS1 preceded AS2 (RFC 4130, 2005) and AS3 (RFC 4823, 2007). It demonstrated that EDI over the internet could deliver non-repudiation and confidentiality without a VAN.
Use
Today AS1 is residual: SMTP latency and the fragility of email store-and-forward made AS2 dominant in internet B2B. A few healthcare and government niches keep AS1 for historical archive reasons.