From a z/OS perspective, the DLSw configuration and definitions reside on the router. As a network administrator, you normally would not get involved with these definitions, because the group responsible for the WAN does them. You need to interact with this group to get MAC addresses of SNA devices and especially the SDLC virtual MAC addresses that the mainframe uses to initiate the LLC2 connection.

For LAN-attached devices, the VTAM definitions remain the same. When changing the SDLC connection from NCP to DLSw router configuration, the physical connection of the devices (PUs and LUs) changes. The router attaches via the LAN, and in most cases will use the OSA card. VTAM definition has to be altered from an NCP definition to a switched major node that includes the physical unit and the logical units of the SDLC-attached device.