ABCs of z/OS System Programming

This IBM Redbooks publication describes the functions of z/OS Communications Server.
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 networking protocols for z/OS. The SNA protocols are provided by VTAM and include Subarea, Advanced Peer-to-Peer Networking, and High Performance Routing protocols.
z/OS Communications Server exploits z/OS UNIX services even for traditional MVS environments and applications. Prior to utilizing TCP/IP services, therefore, a full-function mode z/OS UNIX environment including a Data Facility Storage Management Subsystem (DFSMSdfp), a z/OS UNIX file system, and a security product (such as Resource Access Control Facility, or RACF) must be defined and active before z/OS Communications Server can be started successfully.
The ABCs of z/OS System Programming is a 13-volume collection that provides an introduction to the z/OS operating system and the hardware architecture. Whether you are a beginner or an experienced system programmer, the ABCs collection provides the information that you need to start your research into z/OS and related subjects. If you want to become more familiar with z/OS in your current environment, or if you are evaluating platforms to consolidate your e-business applications, the ABCs collection will serve as a powerful technical tool.