Sun Microsystems SunLink SNA 9.1 PU2.1, Руководство по настройке

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C-4 SunLink SNA 9.1 PU2.1 Server Configuration Guide—August 1997
C
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Ethernet local area network - Multiple DSPUs can attach to an Ethernet
local area network and communicate with the host either directly though a
communications controller or indirectly through a 3174 Establishment
Controller. Like IBM Token Ring, Ethernet operates two data link control
sublayers: LLC and MAC (802.3).
C.1.2 Logical Components
The logical components of a hierarchical SNA network are network
addressable units (NAUs). Each NAU has a unique address in an SNA
network. The NAUs are described as follows:
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System Services Control Point (SSCP) - Monitors and controls the entire
SNA network. The SNA Virtual Telecommunications Access Method
(VTAM) implements the SSCP functions. The SSCP activates and deactivates
all the network resources and coordinates the establishment of all sessions
between NAUs.
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Physical Unit (PU) - Provides services to the SSCP to monitor and control
the SNA resources associated with a physical node. Each SNA host,
communications controller, and cluster controller has a PU that manages its
resources.
PU types on SNA hosts and communications controllers are identified by a
subarea number, as defined in the following table.
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Logical Unit (LU) - Entry point through which end users, such as
application programs or terminal users, gain access to the SNA network.
LUs on SNA hosts are typically associated with large applications such as
CICS, TSO, NetView, JES2, and IMS. LUs on cluster controllers send data to
and receive data from the SNA network for terminal users.
Table C-1 Relationships Between PU Types
PU Type Example Description
5 System/370 Host node.
4 3745, 3725 Communications controller
node.
2 3274 Peripheral node.
2.1 AS/400, 3174, Sun
PU2.1 SNA Server Peer node.