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

1R556 - Overview

• 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: