HP General IO Connectivity manual Application L7, Presentation L6, Session L5 Levels

About the X.25 Product

Application (L7), Presentation (L6), and Session (L5) Levels

Application (L7), Presentation (L6), and

Session (L5) Levels

The X.25 link does not provide any components for the general support of the application and presentation levels (levels 7 and 6, respectively), although X.25/9000 PAD Services do provide some of the functionality of these levels.

User-written application programs, Internet Services/Berkeley Services (via BSD Sockets) and NS (via NetIPC Sockets), are accessed by means of TCP or UDP Transport Level (level 4) protocols.

For application level services, you can install OSI Services to run over the X.25 network (for more information, refer to OSI Services documentation). The OTS/9000 product provides access to X.25 for OSI Services. You can install application level services such as Internet/Berkeley Services and Network Services (for more information, refer to the documentation for these products).

BSD IPC (Berkeley Software Distribution InterProcess Communication) allows direct programmatic access to the X.25 packet level (level 3), or TCP/UDP at the transport level (level 4), for user-written application programs.

NetIPC sockets also provides a programmatic interface to TCP/UDP at the transport level.

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