Overview

PSF views TCP/IP-attached printers in the same way it views SNA-attached printers. PSF performs error recovery, handles intervention-required situations, and displays messages exactly as it does for SNA-attached printers.

TCP/IP software provides universal communication services (interfaces) between physical networks and applications. The communication services reside at the network layer and are independent of the topology of the underlying physical network, as Figure 1 shows.

Figure 1. Appearance of the TCP/IP connection between a z/OS host and a printer

This figure shows how the TCP/IP connection performs like a single network between a z/OS host and a printer.

For example, in communications between a z/OS® host and a printer, as in Figure 1, the IP network performs like a single network. In fact, however, the network is physically like that shown in Figure 2.

Figure 2. Actual physical TCP/IP connection between a z/OS host and a printer

This figure shows the actual physical TCP/IP connection between a z/OS host and a printer.

The routing of information is determined on the basis of the IP address, and is performed by IP gateways. After the network is configured correctly, the z/OS host appears to be communicating directly with the TCP/IP-attached printer.

For a more detailed description of Internet Protocol networks, see TCP/IP Tutorial and Technical Overview, GG24-3376.