HP UX SNAplus2 manual Logical Unit Attributes for Sessions

SNA Terms and Concepts

Basic SNA Concepts

Before an SSCP-LU session can be established, the PU controlling the LU must have an active SSCP-PU session with an SSCP on a type 5 node. The SSCP-PU session is used to pass control data and network management data between the PU and SSCP.

CP-CP sessions

In an APPN network, adjacent nodes establish CP-CP sessions. These sessions are used to search for a resource in the APPN network and to maintain topology information (see “APPN Control Point”).

	Logical Unit Attributes for Sessions
	Logical units have attributes that determine how they interact during
	LU-LU sessions. These attributes are determined by the architecture of
	SNA. LUs can be primary or secondary, and dependent or independent.
	Primary and Secondary LUs. To establish a session, one LU
	requests session activation by sending a BIND request to another LU:
	• A primary LU is the LU that sends the BIND request for a given
	LU-LU session.
	• A secondary LU is the LU that receives the BIND request.
	Peer networks do not use a fixed hierarchy of nodes and do not have
	predetermined primary or secondary LUs.
	In a peer network, an independent LU that is participating in multiple
NOTE
	sessions (see “Multiple and Parallel Sessions”) can act as a primary LU
	for one session and a secondary LU in another.

Dependent and Independent LUs. All type 0, 1, 2, and 3 LUs are dependent LUs. Type 6.2 LUs can be configured as either dependent or independent LUs.

•A dependent LU (also known as an SSCP-dependent LU) requires the services of an SSCP to establish a session with another LU. An SSCP-LU session must be established before a dependent LU-LU session can be established.

A dependent LU can be in session only with LUs on an SNA host. Because of this restriction, dependent LUs usually use subarea networks (also known as host-mediated networks). However, the

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