Communication Protocols

For data to be exchanged smoothly and securely, both the connection and the protocol need to work together. If your company and a partner aren't using the same protocol, you might need a Value-Added Network (VAN) to bridge them.

AS2 — Applicability Statement 2

AS2 became dominant after Walmart began requiring it from its suppliers in the early 2000s. It transports signed and encrypted EDI payloads over HTTPS, with Message Disposition Notifications (MDNs) acting as receipts. AS2 supports unlimited file sizes and is the default choice for high-volume retail EDI.

SFTP / FTP

SFTP is used for secure, cost-effective batch transfer. It doesn't offer the per-message receipts AS2 does, but it's reliable and handles enormous file sizes. The "S" adds encryption in transit. Plain FTP is still seen in legacy integrations but is no longer recommended.

VANs — Value-Added Networks

A VAN acts as a postal service for EDI. You connect once to the VAN and it routes documents to and from any partner on the same network — even if those partners speak a different protocol. VANs charge per kilo-character or per transaction, so volume matters. They're still common in industries with many small partners.

REST API / HTTPS

Modern API-based EDI uses ordinary HTTPS endpoints. Send EDI in the request body, receive translated JSON in the response. Webhooks deliver inbound documents to your servers as they arrive. No VAN, no FTP server, no certificates to rotate — just keys.

Picking a protocol