Communication Outside Your z/VM System, TSAF, or CS Collection

Your organization may need to share resources with another system or with systems that are not part of the same TSAF or CS collection. These systems may or may not be z/VM® systems—and they could even be non-IBM systems. The Advanced Communications Function for the Virtual Telecommunications Access Method (ACF/VTAM*, or VTAM for short), Group Control System (GCS), and APPC/VM VTAM Support (AVS) provide these types of communications services.
  • ACF/VTAM controls telecommunications activity and interprocessor communications in an SNA network.
  • GCS manages subsystems that support an SNA network and provides an interface between these subsystems and CP. ACF/VTAM runs in a GCS virtual machine on z/VM. GCS is a z/VM component.
  • AVS provides the interface between ACF/VTAM and APPC/VM. AVS is also a z/VM component.
With AVS and ACF/VTAM, a program in a TSAF collection, through APPC/VM, can communicate with:
  • Other programs residing in z/VM systems on different TSAF or CS collections or within an SNA network.
  • Programs on non-z/VM systems in the SNA network.

AVS and VTAM support communications between a TSAF or CS collection and systems in the SNA network because they provide the SNA network with a view of the TSAF or CS collection. To support this type of communication, VTAM and AVS (as well as GCS) are required in a TSAF or CS collection along with CMS and CP.