There are many hardware configurations that support APPC/MVS. For example, several combinations of hardware can link a workstation to an z/OS system. The configuration you choose depends on your intended use of APPC/MVS, the hardware available, and the physical connections already in place.

Figure 1 shows a sample configuration to give you an idea of some connectivity options available through APPC/MVS.

Figure 1. APPC Connectivity Options

The configuration example shows a connection of two z/OS systems and the connection of one of the z/OS systems to many workstations through a communications controller.

Hosts can be connected through a channel-to-channel adapter. The two hosts would be running MVS/ESA SP 4.2 or higher with an appropriate level of VTAM®. In the example, one z/OS system has two LUs defined: SRV1LU01 and SRV1LU02. The other z/OS system has one LU defined, SRV2LU03. Each z/OS system belongs to its own SNA network subarea.

To connect the host to the workstations, a communications controller from the 37x5 family is used. The 37x5 communications controller is installed between the host and the workstation to allow remote communications through Synchronous Data Link Control (SDLC). The 37x5 must be running an appropriate level of NCP. If the 37x5 has a Token Ring interface card (TIC) installed, a Token Ring of workstations can be connected to the 37x5 directly or through a gateway workstation.

An alternative configuration for remote communications is to connect a workstation to a modem, and communicate over the phone lines to another modem, which would then be connected to the 37x5. The 37x5 and all of the connected workstations make up another subarea. Each workstation has its own LU.

Another possible configuration is to arrange multiple workstations in a Token Ring network with a gateway workstation connected to the 37x5 through SDLC and two modems.

Transaction programs communicating through any of the defined LUs can communicate with each other. A transaction program on SRV1LU01 can communicate with a transaction program on SRV1LU02 or SRV2LU03. TPs can communicate between the two z/OS systems, or between an z/OS system and any of the workstations.