This IBM Redbooks® publication describes the connectivity options available for use within and beyond the data center for the IBM Z® family of mainframes, which includes the following systems:

• IBM z17™ ME2
• IBM z17 MER
• IBM z17 ME1
• IBM z16® A01
• IBM z16 A02
• IBM z16 AGZ
• IBM z15® T01
• IBM z15 T02

This book highlights the hardware and software components, functions, typical uses, coexistence, and relative merits of these connectivity features. It helps readers understand the connectivity alternatives that are available when planning and designing data center infrastructures.

The changes to this edition are based on the IBM Z hardware announcement dated July 07, 2026.

This book is intended for data center planners, IT professionals, systems engineers, and network planners who are involved in planning connectivity solutions for IBM® mainframes.

Chapter 1. Introduction

Chapter 2. Channel subsystem overview

Chapter 3. Fibre Channel connectivity

Chapter 4. IBM zHyperLink Express

Chapter 5. IBM Open Systems Adapter and Network Express Adapter

Chapter 6. IBM Open Systems Adapter-Express Integrated Console Controller

Chapter 7. Shared Memory Communications

Chapter 8. IBM HiperSockets

Chapter 9. Coupling links and common time

Chapter 10. Extended distance solutions

Appendix A. Cryptographic solutions

Appendix B. Channel feature attributes

Appendix C. Fiber optic cables