Interoperability with IBM Host Systems
Interoperability with IBM Host Systems |
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APPC can be used to support a wide range of applications including:
AS/400 display sessions are provided through APPC using the 5250 data stream. Computers running SNA Server provide APPC access to AS/400s using 5250 emulation clients. Clients can only communicate with AS/400s using APPC.
To support 5250 services, the local APPC LU acts as an identifier for local SNA Server–based clients; the remote APPC LU identifies the AS/400 system. Figure 10.14 shows the local and remote LUs used for this configuration.
Figure 10.14 Components of 5250 Access Through SNA Server
TN5250 is a Telnet service that allows users to access AS/400 systems over a TCP/IP network using an appropriate TN5250 client terminal emulator. The TN5250 service provided with SNA Server enables any TN5250 client to connect to the AS/400 system by means of SNA Server, without installing or configuring TCP/IP on the AS/400 system, as illustrated in Figure 10.15. Full 5250 terminal emulation functions are supported by the service, as well as fault tolerance and security features similar to those provided with the TN3270 service.
Figure 10.15 TN5250 Access Through SNA Server
Although it is possible to perform file transfers between the client and the host system using $INDFILE or other mechanisms, APPC file transfers offer a robust and high performance alternative to emulator-based solutions.
SNA Server supports three host file transfer mechanisms based on APPC connectivity:
The file transfer method that you choose to deploy depends on the type of host system in your enterprise (mainframe or AS/400) and on the type of file transfer capabilities you wish to provide to your users.
The APPC File Transfer Protocol (AFTP) is a client/server application that provides file transfer capabilities using APPC and LU 6.2 (FTP protocol is used on TCP/IP networks in a similar way). AFTP supports functions similar to standard FTP, including the ability to send, receive, and rename files, as well as to manipulate directories on a remote system.
The AFTP service is installed and configured on the computer running SNA Server (or an SNA Server–based client) to allow AFTP client software (provided with SNA Server) to access specific directories on the server.
For more information about configuring and using AFTP, see the SNA Server version 4.0 documentation.
The FTP-AFTP gateway service gives TCP/IP users the ability to access and manipulate files on a mainframe or an AS/400 using a conventional FTP client without installing TCP/IP on the host, as shown in Figure 10.16. The service transparently converts incoming client FTP requests into AFTP commands and manages the communications and data between the two services. This capability can be used interactively by FTP users, or through applications that need access to SNA host data.
Figure 10.16 APPC FTP and FTP-AFTP Gateway Services
To run the FTP-AFTP Gateway Service, you must first install the FTP or AFTP client software as well as the AFTP service on the SNA Server–based computer.
Users on workstations that do not have the SNA Server Client software installed, but who still require file transfer capabilities with an AS/400 host, can use the Shared Folders Gateway Service provided by SNA Server. With this service, network users can share or store files on the AS/400 system as though it were another volume on the SNA Server–based computer, as shown in Figure 10.17.
Figure 10.17 Using the Shared Folders Gateway Service
