Sun Microsystems SunLink SNA 9.1 PU2.1, Configuration Manual

Page: 242 / 298

C-8 SunLink SNA 9.1 PU2.1 Server Configuration Guide—August 1997
C
Figure C-4 Peer-to-Peer SNA Logical Components
The NAUs are described as follows:
•
PU2.1 Control Point (CP) - Monitors and controls resources within the
PU2.1 nodes. The CP activates and deactivates all the network resources and
coordinates the establishment of all sessions between NAUs.
Note that the DLC components shown in Figure C-4 on page C-8 are not
NAUs. They emulate PUs when connecting to a host in the hierarchical
manner. Therefore, from the perspective of a traditional host, a Sun PU2.1
SNA Server, through its CP and DLC components, functions as a PU2
device.
•
Logical Unit (LU) - Entry port for application and service transaction
programs. The programs can interface directly to end users, or the programs
can be self-contained, facilitating Advanced Program-to-Program
Communication (APPC). For more information about APPC, refer to
Section C.5, “APPC and LUType 6.2,” on page C-11.
Peer PU2.1 nodes can use dependent LUs or independent LUs. Independent
LUs, in conjunction with the PU2.1 CP, can establish sessions and act as
either primary or secondary LUs. Only LUType 6.2 on a PU2.1 node can act
as an independent LU.
Dependent LUs require a host-based SSCP to establish sessions. Dependent
LUs can be LUType 0, LUType 1, LUType 2, LUType 3, or LUType 6.2.
PU2.1
cp
DLC
DLC
SNA transport
network
LU6.2
DLC
DLC
LU6.2
PU2.1
cp