The purpose of this document is to complete the task of introducing Transport Layer Security to z/OS® so IBM Personal Communications (PCOMM) uses TLS security. This document walks you through enabling Tunneled Transport Layer Security (TTLS) on your IBM z/OS for use with a PCOMM TN3270 connection. When you complete this task, you require a certificate to access your TN3270 PCOMM session. You work with the following products and components: TN3270 TCPIP PAGENT INET (maybe) IBM RACF® This document assumes that the reader has extensive knowledge of z/OS security administration and these products and components. This document is part of the Technical Enablement Series that was created at the IBM Client Experience Centers.