How CA XCOM Data Transport Store and Forward Works

Document ID : KB000028000
Last Modified Date : 11/01/2019
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What is a Store and Forward transfer?  When to use it and how it works.  How to determine the success of a Store and Forward Transfer.

CA XCOM Data Transport has the ability to transfer a file from one platform through a mainframe to a third destination. CA XCOM must be installed on all three platforms. This is useful in instances where there is no connectivity between platforms or transfers are between SNA and TCPIP only platforms. An indirect transfer is initiated on non-mainframe platform through a mainframe platform to a final destination. CA XCOM does not support indirect transfers initiated from the mainframe.
  • The Store & Forward function of CA XCOM Data Transport uses CA XCOM's Process Sysout Interface (PSOI) on MVS.
  • The PSOI is a temporary repository for data, which can be a FILE, JOB or REPORT, i.e. you might initiate "SEND FILE, SEND JOB, or SEND REPORT" on one AS/400 with an indirect target of another AS/400
  • The logical "connection" between the initiating and remote systems is by virtue of a "WRITER" or "JES DESTINATION" which is defined on MVS in an XCOM Destination entry. A destination member is required for the final destination and must be enabled.
  • The data does not stay on the JES spool but is written to a temporary dataset with the following naming convention:
  • It is possible to specify your own prefix to replace "XCOMPSO" by using the CA XCOM mainframe parameter "PSOPREF= ". CA XCOM will forward the file to the target system, and the temporary file above is then deleted.
  • The two parts of the transfer do not have to be the same protocol. One may be TCP/IP and the other SNA. Specifying the appropriate parameters in the destination member make this possible.
   Determining the Final Success of Failure of the Transfer

   There is no automatic, in-built method of ensuring the final success or failure of an indirect transfer. Here are 2 methods you can use to find out.

A) Use the mainframe as the focal point of "information gathering and distribution" Use any method to capture appropriate XCOM messages from the MVS SYSTEM LOG ... examples might be- XCOMM0141i, XCOMM0137i and XCOMM0147i

The XCOMM0137i comes with ID=INDIRECT for all indirect transfers and this is a convenient "label" by which to capture all indirect transfers and to report upon the final success or failure. XCOM on MVS has information regarding the incoming and outgoing legs of the indirect transfer. Any method of data capture or analysis may be used, since the information may be collected from the system log, or the XCOM history log, or using SMF records. SMF recording is an XCOM option. The final stage might be to send a file to one, or both AS/400s indicating that the transfer was or was not successful.

B) Use the initiating and target systems, AS/400 to AS/400 in this instance, for information gathering and distribution. If you do not want to rely on the mainframe, but want to manage the entire process from AS/400, you can use XCOM to do your usual indirect transfer, then follow it up with a SEND JOB, where the "job" runs on the target AS/400, and collects messages, or checks the existence of the file on the remote system and then uses XCOM to return a message back to the initiating system.

Additional Information:
Indirect transfers may also be sent using XCOM for VSE or VM as an intermediary, but the process differs somewhat from the process described here because of differences in the environment.