Troubleshoot RFC Error Communication

ERROR: RC=20

The error below is due to the Process Runner not being able to communicate with the SAP System Server. You have to assure that the appropriate network ports are open.

Telnet is the lower level program used in Windows for testing whether the port is open or not.

In Windows 7, you have to manually enable the Telnet. For enabling the telnet, follow the steps given below:

Start

2.	Control Panel

3.	Programs And Features

4.	Turn Windows features on or off

5.	Check Telnet Client

Hit OK

Once the Telnet is enabled, perform the following steps:

1.	Open SAP logon pad, select the desired SAP instance and click Change Item.

2.	Copy the IP address mentioned in the Application server.

Also, consider the system number of the instance.

3.	Open the Command prompt in your Windows system.

4.	Enter Telnet, followed by the IP address of the Application Server and 32XX and 33XX where XX is the system number of SAP instance. See below.

5.	If the connection is successful, you will get a blank screen with blinking cursor.

If you get the connection failed screen, you will get screen like this.

6.	You have to check the connectivity for the both the ports , i.e. for 32XX and 33XX.

7.	If any of the connections fails, kindly communicate with your IT Networking team and ask them to open both the ports.

ERROR RC=27:

If you get the error as below, do the following

1.	Find the IP address of the SAP server which you are trying to access.

2.	Open the Command Prompt and type tracert “IPADDRESS”

3.	You will get something like this:

4.	Replace the DNS with IP address you found in the 1st step in your SAP system properties:

Or you can create a new item on SAP Logon pad with this DNS as Application Server and System Number, System ID you got from step 1.