OSA/SF for VM/ESA is an optionally-installed facility supplied with VM/ESA that allows you to customize the modes of operation of an Open Systems Adapter, a unique type of S/390 channel. In the VM/ESA environment, an OSA can transfer data between TCP/IP and VTAM(r) and host programs and their clients on the local area networks (LANs) that the OSA supports.

OSA/SF for VM/ESA supports the S/390 Open Systems Adapter 2 (OSA-2) and the following LAN media: Ethernet, token-ring, Fiber Distributed Data Interface (FDDI), and Asynchronous Transfer Mode (ATM Forum-compliant LAN emulation). The ATM OSA-2 feature can be customized by OSA/SF to serve as a LAN emulation client (LEC) for Ethernet and token-ring emulated LANs.

The announcement letter for VM/ESA Version 2 Release 2, dated September 10, 1996 stated that the planned availability date for the Open Systems Adapter Support Facility (OSA/SF) under VM/ESA would be in the first quarter of 1997. In reality, OSA/SF has been included on the VM/ESA Version 2 Release 2 product tapes which were made available on December 20, 1996.

However, as shipped, OSA/SF for VM/ESA requires the Language Environment 1.6 runtime libraries. To remove this requirement for the full LE 1.6 product, customers should apply APAR OW24276(PTF UW34661) to OSA/SF for VM/ESA. This will allow OSA/SF for VM to use only those parts of the C run time library that are shipped with the base VM/ESA Version 2 Release 2 product.