If you manage EDI long enough, you learn that protocol decisions linger. The choice you make today shapes how reliably files move, how quickly partners onboard, and how painful growth becomes two or three years down the line.
AS2, SFTP, and REST APIs all have a place in modern EDI. The problem is not choosing the wrong one outright. The problem is using the wrong tool for the job, or locking yourself into a setup that cannot evolve as your systems and partners change.
This article looks at how these protocols behave in real, high-volume environments, particularly for teams running SAP, NetSuite, or Oracle. The focus is practical: what works, what struggles, and where teams tend to get surprised.
Protocol choice is often treated as a technical detail. In reality, it affects operations, finance, and planning more than most teams expect.
Speed matters when orders are time-sensitive. Reliability matters when chargebacks or penalties are on the line. Cost predictability matters when volumes spike or new partners come online. If a protocol introduces delays, monitoring gaps, or billing complexity, the business feels it quickly.
You are not just picking how files move. You are choosing how much friction your EDI operation will carry over time.
AS2 is the most familiar option for many supply chain teams, especially those working with large retailers. It is designed for direct, secure communication between trading partners and includes built-in delivery confirmations. In high-volume environments, AS2 performs well because messages move quickly and acknowledgements reduce uncertainty. When teams talk about confidence in EDI, they are often talking about AS2.
SFTP plays a different role. It is reliable, widely supported, and relatively easy to set up. That simplicity is why it has lasted. But SFTP is built around batch processing. Files are dropped, picked up, and processed on a schedule. For large overnight transfers or legacy integrations, this works fine. For time-sensitive workflows, it often becomes a bottleneck.
REST APIs represent the most modern approach. They are designed for real-time, programmatic communication and fit naturally with cloud-based systems. When both sides support APIs, data moves immediately and errors surface quickly. The challenge is not performance, but adoption. Many trading partners are simply not ready to move away from file-based EDI.
In SAP environments, AS2 remains the most dependable option for core transactional documents. It integrates cleanly and supports the audit requirements many SAP users face. SFTP is still common for legacy connections or bulk data movement, but it is rarely the best choice for just-in-time processes. REST APIs are becoming more important in newer SAP deployments, especially where real-time visibility is a priority.
NetSuite teams tend to run a mix. AS2 is often required by large trading partners, even if NetSuite itself is cloud-native. SFTP remains common for scheduled imports and exports. REST APIs, particularly through SuiteTalk, are well suited for real-time inventory, order status, and newer partner workflows.
Oracle environments show a similar pattern. AS2 is widely used for high-volume transactions in both E-Business Suite and Fusion. SFTP often supports legacy processes or transitional phases. REST APIs are gaining traction in Oracle Cloud deployments, especially where ecommerce and B2B systems need tighter integration.
Read more: Advanced EDI Strategies for SAP, NetSuite, and Oracle.
When you compare these protocols side by side, the differences become clearer in day-to-day use.
AS2 performs best when timing and confirmation matter. Messages move quickly, receipts confirm delivery, and retries are built into the process. This reduces ambiguity and makes it easier to meet strict partner requirements.
SFTP trades speed for simplicity. It is stable, but it assumes someone or something is watching for failures. Without monitoring, problems can go unnoticed. That is manageable in low-risk workflows, but risky in high-volume operations.
REST APIs excel at immediacy. Data moves as soon as it is requested or sent, and errors surface right away. This is ideal for real-time use cases, but only when partners and internal systems are ready to support it consistently.
From a cost perspective, protocol choice can expose weaknesses in your VAN model.
AS2 scales well technically, but some providers attach per-message or per-connection fees that grow quietly as volume increases. SFTP handles large batches without issue, but often requires more manual oversight as complexity grows. REST APIs are designed for scale, but API limits and ERP constraints need to be managed intentionally.
The protocol itself is rarely the cost problem. The pricing model around it usually is.
Most organizations do not choose one protocol and move on. They layer them.
AS2 remains the backbone for major trading partners. SFTP stays in place for legacy systems and batch jobs. REST APIs are introduced gradually for new, cloud-based workflows.
This hybrid approach works well when your VAN supports all three without friction. It breaks down when you are forced to overuse one protocol because others are not supported or priced reasonably.
Teams that migrate successfully tend to follow a few consistent practices. They avoid all-at-once transitions, demand visibility into message flow and billing, and insist on full protocol support before committing to a provider. Most importantly, they document and automate monitoring so failures are caught early, regardless of protocol.
Modernizing EDI does not require ripping everything out. It requires control and visibility while change happens incrementally.
Protocol choice is only one piece of a stable EDI strategy. You also need a VAN that supports mixed environments, clear monitoring, and predictable costs as your operation evolves.
At Nexus VAN, AS2, SFTP, and REST APIs are supported under a single platform, with an emphasis on clarity and responsiveness. That allows teams to modernize at their own pace without introducing new uncertainty.
If you want to review how your current protocol mix is performing or talk through a lower-risk path forward, we are happy to walk through it with you.
