Connecting multiple networks using SNA network interconnection
A multiple-network environment consists of multiple independent SNA subarea networks that are interconnected. The SNA network interconnection (SNI) facility enables communication between these separate networks.
- Gateway VTAMs
- Gateway NCPs
CDRM major nodes and NCP major nodes, together with VTAM® start options, are used to define these resources. For a full discussion of SNA network interconnection and how to define these resources for various types of SNI configurations, see the z/OS Communications Server: SNA Network Implementation Guide.

The sample CDRM major node definitions that follow and the CDRM major node for A01N in Dynamically defining cross-domain resources, together with the PATH definitions and the associated NCP major node definitions, are necessary to allow LU-LU sessions to be set up among the subarea-capable nodes in the network shown in Figure 1. You will find the PATH definitions for these same nodes in Path definition statements.