Expand Configuration and Management Manual (G06.24+)

Subsystem Control Facility (SCF) Commands
Expand Configuration and Management Manual—523347-008
15-3
Expand Subsystem Objects
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The path function corresponds to the functions defined by Layers 3 and 4 of the
Open Systems Interconnection (OSI) Reference Model. You specify the PATH
object when you want to display Layer 3 and 4 information or alter Layer 3 and 4
attributes for a single-line Expand line-handler process.
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The line function corresponds to the functions defined by Layer 2 of the OSI
Reference Model. You specify the LINE object when you want to display Layer 2
information or alter Layer 2 attributes for a single-line Expand line-handler process.
Multi-Line Paths
A multi-line path consists of multiple logical devices: a single logical device manages
the path function (called a path logical device) and separate logical devices (called
line logical devices) manage each of the lines in the path.
You must specify the PATH object when you want to manage a path logical device and
the LINE object when you want to manage a line logical device. The LINE object is
subordinate to the PATH object when it describes a line logical device.
Multi-CPU Paths
A multi-CPU path consists of up to 16 individual Expand paths, including multi-line
paths. Each Expand line-handler process (or multi-line path) that is a member of a
multi-CPU path is configured in a different processor.
You use SCF commands to manage multi-CPU paths in the same way that you use
SCF commands to manage single-line Expand line-handler processes.
Expand-Over-NAM, IP, ATM, ServerNet, X.25, and FOX Connections
Expand-over-NAM, Expand-over-IP, Expand-over-ATM, Expand-over-ServerNet,
Expand-over-X.25, and Expand-over-FOX line-handler processes use the Layer 2 (line
function) services of another process. For example, an Expand-over-X.25 line-handler
process uses the Layer 2 services provided by an X25AM line-handler process.
LINE and PATH Object Names
A LINE object name can be the device name of an Expand line-handler process that
manages a single line, or it can be the device name of a line logical device (a line in a
multi-line path).
A PATH object name can be the device name of an Expand line-handler process that
manages a single line, or it can be the device name of a path logical device.
Note. For more information about how the Expand subsystem relates to the OSI Reference
Model, refer to Expand Subsystem and the OSI Reference Model on page 18-9.
Note. SCF will return an error message if you try to use the LINE object to manage a path
logical device or the PATH object to manage a line logical device.