SNAX/APC Application Programming Manual

Using the Application Program Interface
SNAX/APC Application Programming Manual—138786
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Local Target TP Example
Local Target TP Example
The local SNAX/APC process can receive an ATTACH request from a remote TP in two
instances:
•
The local TP exists and is waiting for an ATTACH request from a remote TP.
•
The local TP does not exist but is created by the Dispatcher on receipt of a remote
ATTACH request.
Figure 1-4
illustrates the situation in which the local TP already exists.
1. The local TP sends to SNAX/APC a TP-READY request specifying
LOCAL-ATTACH=N, DISPATCHED=N.
The request should also indicate either a specific local LU by specifying an LU
name in the TR-APC-LUNAME field, or a general LU by specifying an asterisk (*)
in the TR-APC-LUNAME field.
The SNAX/APC process receives the TP-READY request from the local TP,
indicating a wait for a remote ATTACH request. The SNAX/APC process checks
for a previously received ATTACH request and, finding none, places the TP-
READY request in an internal queue.
If the TP-READY request is a specific request and the SNAX/APC server finds no
pending attach request on the specified LU, it puts the TP-READY request on an
internal queue of specific TP-READY requests. If the TP-READY request is a
general request and the SNAX/APC server finds no pending attach request for any
LU, it puts the TP-READY request on an internal queue of general TP-READY
requests.
2. The remote TP is ready to send data to local TP. The first step is to send an
ALLOCATE request to the remote LU, in this case CICS.
3. The remote TP sends the data to the remote LU.
Figure 1-4. Waiting for a Conversation
004CDT .CDD
SNA
IBM Tandem
Remote TP Local TP
TP-READY request
TP-READY
reply
ATTACH (data)
ALLOCATE
SEND DATA
CICS SNAX/APC
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