Choosing Between AS2, SFTP, and VANs: What’s the Right Communication Protocol?
Electronic Data Interchange doesn’t fail because of bad standards. It fails because of bad plumbing. The communication protocol you choose (AS2, SFTP, or a VAN) defines how reliably, securely, and scalably your EDI actually moves between partners.
There’s no universal “best” option. There is only the option that best fits your business reality.
AS2 (Applicability Statement 2)
AS2 (Applicability Statement 2) is a direct, point-to-point protocol designed specifically for EDI. It works over HTTPS and supports encryption, digital signatures, and Message Disposition Notifications (MDNs), which confirm successful delivery. This makes AS2 popular in retail, manufacturing, and any environment where non-repudiation matters.
SFTP (Secure File Transfer Protocol) is simpler and more flexible. Files are placed on a secure server and picked up by the trading partner. It’s widely supported, easy to automate, and familiar to IT teams. Many organizations start with SFTP because it’s quick to deploy and inexpensive.
The downside is visibility. SFTP confirms that a file was transferred, not that it was processed. There’s no native acknowledgment, which means errors often surface late, usually during reconciliation or partner complaints.
VANs (Value-Added Networks)
VANs (Value-Added Networks) act as intermediaries. They receive, validate, route, and track EDI traffic between trading partners. VANs shine in multi-partner environments where onboarding speed, message tracking, and support matter more than raw cost. They also reduce the operational burden on internal teams.
The cost model is the catch. VANs typically charge per kilo-character, document, or connection, which can grow expensive at scale. You’re also dependent on a third party for routing and delivery performance.
So how do you choose?
If you have a small number of high-volume partners and strong IT governance, AS2 offers control and compliance. If speed, simplicity, and low setup effort matter most, SFTP is often enough, especially for internal or low-risk exchanges. If you manage many partners with different capabilities, a VAN reduces friction and operational noise.
The real mistake isn’t picking the “wrong” protocol. It’s assuming one protocol will fit every partner, every workflow, and every growth stage. Mature EDI ecosystems often use all three — by design, not by accident.