Communications Server for z/OS V1R7 TCP/IP Implementation, Volume 1: Base Functions, Connectivity, and Routing

Chapter 1. Introduction 3

򐂰 The ISHELL, which is an ISPF interface with access to menu-driven command interfaces

The TCP/IP protocol suite is implemented by an MVS started task within the TCP/IP address

space in conjunction with z/OS UNIX (UNIX System Services).

A CS for z/OS IP environment requires a Data Facility Storage Management Subsystem

(DFSMS), a z/OS UNIX file system, and a security product such as Resource Access Control

Facility (RACF). These resources must be defined and functional before the z/OS

Communication Server can be started successfully and establish the TCP/IP environment.

We later mention the manner in which these products impact a CS for z/OS IP environment.

1.1.2 For additional information

The following IBM publications provide further details for implementing a z/OS environment

that supports the TCP/IP protocol suite:

򐂰 z/OS V1R7.0 Communications Server: New Function Summary, GC31-8771

򐂰 z/OS V1R7.0 Communications Server: IP Configuration Reference, SC31-8776

򐂰 z/OS V1R7.0 Communications Server: IP Configuration Guide, SC31-8775

򐂰 z/OS V1R7.0 Communications Server: IP Sockets Application Programming Interface

Guide and Reference, SC31-8788

1.2 Why CS for z/OS IP is important

The z/OS Communications Server provides a high-performance, highly secure, scalable, and

reliable platform on which to build and deploy networking applications.

CS for z/OS IP is important because it offers an environment that is accessible to the

enterprise IP network and the Internet if so desired. It defines the z/OS environment as a

viable platform by making z/OS applications and systems available to the non-z/OS

environment, which are typically UNIX/Windows® centric. Consequently, it eliminates the

issues and challenges of many large corporations to migrate or integrate with a more

accessible platform and newer technologies. Many technologies have been implemented in

the z/OS environment to complement TCP/IP. Some of these include:

򐂰 High-speed connectivity, such as:

– OSA-Express Gigabit Ethernet or 1000BASE-T in QDIO mode

– High-speed communication between TCP/IP stacks running in logical partitions using

HiperSockets

򐂰 High availability for applications using Parallel Sysplex technology in conjunction with:

– Dynamic Virtual IP Address (

VIPA), which provides TCP/IP application availability

across z/OS systems

in a Sysplex and allows participating TCP/IP stacks to provide

backup and recovery for each other, for planned and unplanned TCP/IP outages

–

Sysplex Distributor, which provides intelligent load balancing for TCP/IP application

servers

in a Sysplex, and along with Dynamic VIPA provides a single system image for

client applications connecting to those servers

– The Load Balancing Advisor (LBA), which provides z/OS Sysplex server application

availability and performance data to

outboard load balancers via the Server

Application State Protocol

(SASP)