SNA Link/iX Node Managers Guide (30291-90009)

Table Of Contents

16 Chapter1

SNA Links Overview

SNA Layers Implemented

The SNA services implement the upper layers of the SNA architecture.

SNA Transport implements a type 2.0 (T2.0) node (formerly called a

Physical Unit Type 2 [PU.T2]) and type 2.1 (T2.1) node (formerly called

a Physical Unit Type 2.1 [PU 2.1]) for SNA/SDLC Link, a T2.0 node for

SNA/X.25 Link, and a T2.0 and T2.1 for SNA/Token Ring Link. (Note

that, at this time, LU 6.2 API/XL is the only SNA service that makes

use of the T2.1 node capabilities.) SNA Transport also includes the Path

Control and Transmission Control layers of SNA, as well as the

Conﬁguration Services and Address Space Manager functions. It

provides a direct send/receive interface for the SNA services to

establish LU-LU sessions with the remote system. So, the lower layers

of SNA are implemented by running the services with an SNA link.