Sun Microsystems SunLink SNA 9.1 PU2.1, Configuration Manual

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1-10 SunLink SNA 9.1 PU2.1 Server Configuration Guide—August 1997
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SDLC and QLLC connections - For point-to-point lines, you can configure
one PU for each line. For multi-point lines, you can configure multiple PUs
for each line.
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Channel connections - You can configure multiple PUs on the channel. Each
PU uses a separate subchannel address.
A PU2/PU2.1 emulated by the Sun PU2.1 SNA Server is activated by the IBM
mainframe Virtual Telecommunications Access Method (VTAM). VTAM
establishes a System Services Control Point (SSCP)-to-PU control session with
each PU2/PU2.1 during activation. The server maintains the SSCP-PU control
session and opens an interface to allow client programs to access it.
For more information about configuring PUs, refer to Chapter 7, “Configuring
PUs.”
1.6 LU Emulation
The Sun PU2.1 SNA Server supports both dependent LUs and independent
LUs, as follows:
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Dependent LUs - Each PU2.1 device can support the following types of
dependent LU: LUType 0, LUType 1, LUType 2, LUType 3, and LUType 6.2.
VTAM activates the dependent LUs, which rely on the SSCP-PU control
session for activation and session initiation. During activation, the IBM
mainframe establishes an SSCP-LU control session with each activated
dependent LU. The server maintains the SSCP-LU control session and opens
an interface to allow client programs to access it.
The server assists in the establishment of dependent LU-LU sessions. An
IBM mainframe application (primary LU) asks to bind with a client program
(secondary LU). If a client program is present at the LU, the server
establishes an SNA session.
You can group dependent LUs into LU pools to control access to the
dependent LUs. For more information, refer to the following section.
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Independent LUs - Independent LUs are activated locally either through
auto-activation or through operator control. Independent LUs can be
LUType 6.2 only.