How To Fix 1R556 - Communication error in RFC call of function module &1

SAP Error Message - Details

• Message type: E = Error

• Message class: 1R - SAP Knowledge Provider

• Message number: 556

• Message text: Communication error in RFC call of function module &1

What causes this issue?

Calling function module &V1& by remote function call (RFC) triggered
the exception COMMUNICATION_FAILURE. This happens when a problem has
occurred in establishing the connection or in communication.

System Response

The function module was not executed.

How to fix this error?

Repeat the operation that led to this error (after waiting a certain
period of time, if necessary). If the error reoccurs, inform system
administration.

Procedure for System Administrators

Check the abvailability of the target system of the RFC call. If this
message is in the application log, you may find more entries on RFC
destinations and on relevant operating system error messages.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message 1R556 - Communication error in RFC call of function module &1 ?

  The SAP error message 1R556 indicates a communication error in an RFC (Remote Function Call) when trying to call a function module. This error can occur due to various reasons, and understanding the cause is essential for troubleshooting. Here are some common causes, potential solutions, and related information:
  Causes:
  
  Network Issues: There may be network connectivity problems between the SAP systems involved in the RFC call.
  RFC Destination Configuration: The RFC destination may not be configured correctly in the SAP system. This includes incorrect settings for the target system, such as the hostname, system number, or client.
  Authorization Issues: The user credentials used for the RFC call may not have the necessary authorizations to execute the function module.
  Function Module Issues: The function module being called may not exist in the target system, or it may be inactive.
  System Load: High load on the SAP system can lead to timeouts or communication failures.
  Firewall or Security Settings: Firewalls or security settings may be blocking the communication between the systems.
  
  Solutions:
  
  Check Network Connectivity: Ensure that there is proper network connectivity between the systems. You can use tools like ping or traceroute to diagnose network issues.
  Verify RFC Destination:
  
  Go to transaction SM59 in the SAP GUI.
  Check the configuration of the RFC destination being used. Ensure that the connection parameters (like hostname, system number, and client) are correct.
  Test the connection using the "Test Connection" button in SM59.
  
  
  Review Authorizations: Ensure that the user ID used for the RFC call has the necessary authorizations to execute the function module. You can check this in transaction SU53 after the error occurs.
  Check Function Module: Verify that the function module exists in the target system and is active. You can check this in transaction SE37.
  Monitor System Performance: Use transaction SM50 or SM66 to monitor system performance and check for any locks or long-running processes that might be affecting the RFC call.
  Firewall Settings: If applicable, check firewall settings to ensure that the necessary ports for RFC communication are open.
  
  Related Information:
  
  Transaction Codes:
  
  SM59: RFC Destinations
  SE37: Function Module
  SU53: Authorization Check
  SM50/SM66: Process Overview
  
  
  SAP Notes: Check for any relevant SAP Notes that might address specific issues related to RFC communication errors.
  Logs: Review system logs (transaction SM21) for any additional error messages or warnings that might provide more context about the issue.
  
  By following these steps, you should be able to identify and resolve the cause of the RFC communication error. If the problem persists, consider reaching out to your SAP Basis team or SAP support for further assistance.