SNAX/XF and SNAX/APN Configuration and Management Manual

Attributes for SNAX/XF and SNAX/APN
SNAX/XF and SNAX/APN Configuration and Management Manual—425836-006
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PUIDBLK (PU Objects) - for SNAX/APN
The default value, %hFFF, indicates that SNAX/XF does not perform SDLC XID
verification for a PU unless the PU is subordinate to a switched secondary line, in
which case SNAX/XF sends the default value to the host in the SNAX/XF XID
response.
For nonswitched lines, XID exchanges are not supported, and only the default values
for PUIDBLK and PUIDNUM are allowed.
PUIDBLK (PU Objects) - for SNAX/APN
When applied to PU objects, PUIDBLK specifies the identification block of the remote
link station. Together, the PUIDBLK and PUIDNUM attributes can be used in Exchange
Identification (XID) validation.
The default value %hFFF (or the specification %h000) signifies that the NonStop node
does not expect a unique node identifier. Thus, when PUIDBLK is allowed to default,
the NonStop node will excuse from validation any XID Format 3 (XID3) frame if that
frame uses identification number/identification block validation, rather than validation
by control point name/SNA network identifier.
The NonStop node attempts to validate an incoming XID3 frame by using the PUIDBLK
and PUIDNUM specifications only when the following conditions are true:

The NonStop node does not receive a control point name or SNA network identifier
in the XID3 frame from the adjacent node.

The identification block defined on the NonStop node to represent the adjacent
node is neither X’000’ nor X’FFF’. The NonStop node is defined as %hFFF
whenever PUIDBLK is allowed to default.
When these conditions are true, the value for PUIDBLK must match the value specified
in the parameter in which the adjacent node defines its own identification block. The
name and location of this parameter varies by IBM system type. Therefore, the
following matches must be made:

AS/400 systems, and PS/2 systems running OS/2: The SCF PUIDBLK
specification for the remote PU object must match the EXCHID parameter of the
Line Description, where the identification block and identification number are
defined together.

Systems using NCP and VTAM: For the matching parameters, consult the IBM
document for the version and release of VTAM and NCP on your system.
When link stations negotiate their roles, XID validation takes place before negotiation
occurs. SNAX/APN differs from SNAX/XF in that XID validation takes place on both
switched and nonswitched lines.
Default: %hFFF
Value: %h001 - %hFFE
Objects: PU