IBM OS/390 User Manual

First of all, configure the UNIX System Services (part of the OS/390 base product)
in order to enable TCP/IP on OS/390. As a second step you will have to
customize TCP/IP on OS/390.

On VSE/ESA, almost all TCP/IP customization information is located in one file,
the IPINIT.L initialization file. It contains all the required TCP/IP definitions such
as the physical network, links, routing tables, user IDs, and TCP/IP daemons.

On OS/390, the TCP/IP definitions are located in several data sets. This is why
you have to customize several data sets in order to migrate your VSE/ESA
TCP/IP definitions. Mainly, you have to provide the:

•

TCPIP.PROFILE (TCP/IP definitions for the physical network, network routing,
TCP/IP stack and so on)

•

TCPIP.DATA (parameters for all TCP/IP server and client functions)

•

depending on your requirement, some other configuration data sets such as
HOSTS.LOCAL (host name to IP address mapping) and other etc files have to
be set up.

All TCP/IP for VSE standard applications such as Telnet, FTP or LPR/LPD, are
also available with TCP/IP on OS/390. The HTTP server on OS/390 is provided by
the Domino Go Web Server or the ICSS (Internet Connection Secure Server).
Therefore, migrating to OS/390 doesn

′

t restrict the TCP/IP server and client

functionality and can be done with low effort. However, OS/390 users can make
use of additional TCP/IP functions such as REXEC, DCE or SMTP.

Don

′

t forget to move your data files that are exclusively used/accessed through

TCP/IP. If you have, for example, set up VSE/ESA as a Web server, consider to
move the Web server data such as HTML documents, and graphics that are
stored in VSE library members or VSAM files. These files should be moved into
OS/390 HFS (Hierarchical Filesystem) data sets. Transferring the files could, for
example, be done using the FTP function.

If you are using batch jobs on VSE to automate TCP/IP client commands such as
LPR printing, FTP to automatically transfer files or the Telnet client to access
remote TCP/IP systems, take into account that you will have to migrate these
batch jobs as well. For the OS/390 system, you have to convert your batch jobs
to CLISTs, REXX EXECs or UNIX shell scripts.

If you have many user written TCP/IP applications on your VSE/ESA system, the
migration effort can be considerably high depending on the TCP/IP interface that
has been used.

Chapter 9. Telecommunications S u b s y s t e m s