Proposed Architecture for File Transfer into SAP Private Cloud

Options Evaluated for SFTP Integration

1. Integration Suite with SAP S/4 SFTP Folder (via Cloud Connector)

• Mechanism:
• Configure the file server as a target in the SAP Cloud Connector.
• SAP Cloud Connector acts as a reverse proxy, routing SFTP traffic securely to the mapped directory in the SAP S/4 system.
• Pros:
• Low cost; leverages existing components.
• Secure and scalable.
• Cons:
• Adds configuration complexity.
• Slight latency due to indirect communication.

2. Direct Integration via SAP BTP (without Cloud Connector)

• Mechanism:
• Raise a Service Request (SR) to SAP for:
• Provisioning an SFTP server alongside the SAP system.
• Setting up a Hyperscaler Load Balancer (LB) for inbound traffic to expose the SFTP service.
• Whitelist up to 5 IPs or URLs for security approval.
• Use port 22 for communication.
• Pros:
• Direct, streamlined integration.
• Preferred by SAP for long-term scalability and best practices.
• Enhanced security with Load Balancer IP filtering.
• Cons:
• Higher costs for BTP services, SFTP provisioning, and Load Balancer setup.
• Requires SAP security team approval for SRs.

Typical Customer Scenarios

• On-Premise Connections:
• Most customers connect to the ECS-hosted SFTP share from their on-premise network. This involves internal routing and does not require exposing traffic to the public Internet.
• Public Internet Connections:
• Customers occasionally request to enable port 22 traffic between a public Internet IP and the ECS SFTP share. Such requests can include:
• Inbound Port 22 Traffic:
• From a public Internet IP to the ECS virtual machine (VM).
• Requires careful IP whitelisting to ensure secure access.
• Outbound Port 22 Traffic:
• From the ECS VM to a public Internet IP.
• Requires an external outbound Load Balancer to handle the traffic.

Key Notes from SAP Architects

• Port 22 Restrictions:
• SAP allows a maximum of 5 whitelisted IPs or URLs for port 22 traffic.
• Requests exceeding this limit will be rejected.
• Even for requests under the limit, SAP's security team will review and approve or deny based on risk assessments.
• External Outbound Load Balancer:
• For outbound traffic (e.g., ECS VM to an Internet IP), customers must request SAP to provision an external outbound Load Balancer as part of the service request.

Recommendations

For cost-sensitive or time-critical setups: Use Option 1 (Integration Suite via Cloud Connector).

For a robust, scalable solution that aligns with SAP’s best practices: Use Option 2 (Direct Integration via BTP), considering the additional setup time and costs.

Next Steps

1. Confirm the architectural choice based on project priorities, budget, and timelines.

2. If Option 2 is selected:

• Raise the necessary SRs for SFTP server provisioning, inbound/outbound Load Balancer setup, and IP whitelisting.
• Define IP filtering rules, ensuring compliance with SAP’s security requirements.

3. Test and validate the architecture end-to-end for secure SFTP file transfers.