VTAM application program as part of an SNA network

Figure 1 shows an example of a VTAM® application program as part of an SNA network. (An SNA network is the part of a user-application network that conforms to the formats and protocols of SNA. It enables you to transfer data reliably among end users and provides protocols for controlling the resources of various network configurations.) The numbers in Figure 1 refer to major parts of the system and are described in the text that follows.

A VTAM application program can communicate with the following:

Other VTAM application programs
SNA devices (channel-attached and SDLC link-attached)
Non-SNA 3270 devices (channel-attached and BSC link-attached)
Non-SNA devices in conjunction with the Network Terminal Option (NTO) licensed program
LUs controlled by another VTAM

When the unqualified term logical unit is used in this book, it refers to any or all of the above. In general, the term device-type LU refers to any LU other than an application program.

Figure 1. VTAM application programs in an SNA network

The diagram shows an example of a VTAM application program as part of an SNA network with numbers referring to major parts of the system.