SNAX/APC Configuration and Management Manual

Using SNAX/APC
SNAX/APC Configuration and Management Manual—138787
3-10
Configuration Parameters for SNAX/APC
values. If a MAXOUTRUSIZE value is not specified for an individual PTNR-
MODE object, it gets this value.
If SNAX/APC is the primary LU, it sends this value in the BIND request.
If SNAX/APC is the secondary LU, its BIND response returns the lesser of
MAXOUTRUSIZE and the BIND RU size. If the BIND RU size is less than 16,
SNAX/APC returns 16.
The relation between the value of MAXOUTRUSIZE and the PU RECSIZE (which
is specified in the SCF configuration for the underlying access method) controls
whether or not SNAX/APC will send segmented RUs to the remote LU.
SNAX/APC will send segmented RUs if MAXOUTRUSIZE plus FID2 TH
(Transmission Header for FID2 is 6 bytes) is greater than the PU RECSIZE
(specified in SCF). If the remote LU does not support segmentation, you must
ensure that MAXOUTRUSIZE plus TH is less than the PU RECSIZE. SNAX/APC
will send segmented RUs even if the remote LU specifies in the BIND (or BIND
response) that it does not support segmented RUs.
It should be noted that the above discussion is a slight oversimplification.
SNAX/APC does not actually do the segmentation, it is the underlying SNA access
method (typically SNAX/XF) that may segment the BIU into multiple PIUs.
ONESTEPREAD { ON | OFF }
allows the use of one-step reads. ONESTEPREAD ON is the default setting. One-
step reads significantly improve throughput by speeding up each read. The size of
the read is set to MAXINRUSIZE (in bytes).
The only disadvantage to use is that the user will have to take note of the extra use
of PFS—the file space reserved for the SNAX/APC process—if the number of
concurrent sessions (with outstanding reads) approaches the process limit of 1024.
To switch off the default, enter PARAM ONESTEPREAD OFF.
REMOTEATTACH { QUEUE | REJECT }
specifies whether remote ATTACH requests are queued if there are no outstanding
TP-READY requests. QUEUE specifies that the remote ATTACH requests
designated to TPNs are queued if there are no outstanding remote-attached TP-
READY requests. REJECT specifies that the remote ATTACH requests designated
to TPNs will be rejected if there are no outstanding remote-attached TP-READY
requests. The default value is QUEUE.
This startup PARAM sets the default value for all TPNs. The SCF or SPI command
ALTER TPN can override this default for a selected TPN.
RMATTACHTIMER number
specifies the time (in milliseconds) within which a TP-READY must arrive to satisfy
a queue ATTACH before the ATTACH is rejected —when REMOTEATTACH is
QUEUE. The allowable values are -1 and from 1 to 86400000 (24 hours). The
default is -1, which represents an infinite amount of time.