Resource definition for transaction routing using indirect links

The resource definitions that are required to establish a transaction-routing path between a terminal-owning region SYS01 and an application-owning region SYS04 via two intermediate systems SYS02 and SYS03, using indirect links, are shown.

The resource definitions required are shown in Figure 1. For clarity, the figure shows hard-coded remote terminal definitions that do not use the REMOTESYSNET option (if REMOTESYSNET is used, indirect links are not required). Shippable terminals could also be used.

Figure 1. Defining indirect links for transaction routing
A chain of four CICS regions are connected by MRO or APPC links. There is a TOR (SYS01), two intermediate regions (SYS02 and SYS03), and a back-end AOR (SYS04). There are direct links between SYS01 and SYS02, SYS02 and SYS03, and SYS03 and SYS04. On the AOR (SYS04), there is an indirect link to the TOR (SYS01), by way of SYS03. On SYS03, there is an indirect link to the TOR by way of SYS02. On the TOR, a terminal is defined as local. On all the other regions, it is defined as remote, owned by the TOR.

Defining the direct links

The direct links between SYS01 and SYS02, SYS02 and SYS03, and SYS03 and SYS04 are MRO or APPC links defined as described in Defining links for multiregion operation and Defining APPC connections.

Defining the indirect links

Indirect links to the terminal-owning region (TOR) can be defined to some systems in a transaction-routing path and not to others, depending on the structure of your network and how you have coded your remote terminal definitions.

For example, if an intermediate system uses hard-coded terminal definitions that do not specify REMOTESYSNET and the system does not have a direct link to the TOR, an indirect link is required. Indirect links are never required in the system to which the TOR has a direct link.

In the current example, indirect links are defined in SYS04 and SYS03. The following rules apply to the definition of an indirect link:
  • ACCESSMETHOD must be INDIRECT.
  • NETNAME must be the applid of the terminal-owning region.
  • INDSYS (meaning indirect system) must name the CONNECTION name of an MRO or APPC link that is the start of the path to the terminal-owning region.
  • No SESSIONS definition is required for the indirect connection; the sessions that are used are those of the direct link named in the INDSYS option.

Defining the terminal

If shippable terminals are used, no remote terminal definitions are required.

For the recommended methods to define remote terminals and connections to a CICS Transaction Server for z/OS® system, see Defining remote resources.

Figure 1 shows hard-coded remote terminal definitions that do not specify the REMOTESYSNET option. If you use these terminal definitions, the following conditions apply:
  • The REMOTESYSTEM (or SYSIDNT) option in the remote terminal or connection definition must always name a link to the TOR (that is, a CONNECTION definition on which NETNAME specifies the applid of the terminal-owning region).
  • The named link must be the direct link to the terminal-owning region, if one exists. Otherwise, it must be an indirect link.

Defining the transaction

For information about the definition of remote transactions, see Defining remote resources.