Upgrading to Rfc Connector 3.0 and Netweaver RFC (NWRFC)

Abstract: This knowledgebase entry describes the differences between the two RFC libraries offered by SAP, and discusses possible update strategies for users of Rfc Connector.

Differences between „classic“ and NetWeaver RFC library

Up to SAP GUI 7.40, SAP shipped the „classic“ RFC library (librfc32u.dll). However, starting with SAP GUI 7.50, the classic RFC library is replaced by the NetWeaver RFC library, which offers improved performance and stability, and, unlike its predecessor, supports complex parameters (e.g. nested tables and structures).

The Netweaver RFC library is distributed along with SAP GUI 7.50 and later, and can also be obtained as a standalone download from the SAP marketplace. It consists of the following files:

  • sapnwrfc.dll
  • icudt34.dll
  • icuin34.dll
  • icuuc34.dll
  • libicudecnumber.dll
  • libsapucum.dll

Migrating to the NWRFC library

As of Rfc Connector 3.0, the NetWeaver RFC library is fully supported by Rfc Connector with the new NWRfcSession and NWRfcServer classes. These classes act as a drop-in replacement for RfcSession and RfcServer. Therefore, to upgrade your program to use the NWRFC library, the following steps are necessary:

  1. Upgrade Rfc Connector to 3.0 or later
  2. Replace all occurrences of RfcSession with NWRfcSession
  3. Replace all occurrences of RfcServer with NWRfcServer

You can obtain Rfc Connector 3 as usual through the download page. Note that you can not use Rfc Connector 2 license keys for Rfc Connector 3. You can obtain a new license key through the order page, either free of charge (if you have a current support extension) or for a reduced upgrade fee.

Adding ABAP permissions for SDIFRUNTIME

NWRfcSession needs an additional S_RFC permission to access the function group SDIFRUNTIME. This was not necessary with RfcSession. If you get an error message like


you need to add this permission to your SAP user‘s profile.