z/OS® Communications Server provides a set of communications protocols that support peer-to-peer connectivity functions for both local and wide-area networks, including the most popular wide-area network, the Internet. z/OS Communications Server also provides performance enhancements that can benefit a variety of TCP/IP applications.
z/OS Communications Server provides both SNA and TCP/IP protocols for z/OS. The SNA protocols are provided by VTAM® and include Subarea, Advanced Peer-to-Peer Networking, and High Performance Routing protocols. For more information about z/OS Communications Server SNA protocols, see z/OS Communications Server: SNA Network Implementation Guide.
Figure 1 shows the z/OS Communications Server TCP/IP protocol suite (also called stack), whose functions include associated applications, transport- and network-protocol layers, and connectivity and gateway functions. z/OS Communications Server contains IPv6 support. See z/OS Communications Server: IPv6 Network and Application Design Guide for more detailed information.
The application categories in Figure 1 do not list every application of the TCP/IP protocol suite.