Tuning is the process of balancing the network load among resources to eliminate congestion in any one resource. You need to tune VTAM® to give you optimal service while using the least amount of resources. The objectives of tuning are to use storage in the host processor and in the communication controller more efficiently and to lessen the load on the host processor. For example, to use storage more efficiently, you should avoid allocating too many VTAM buffers in the host and choose a more appropriate buffer size in the communication controller.

The elements of a network can be regarded as a series of related storage spaces. A host processor provides storage for VTAM and application programs. Communication controllers contain storage for NCPs and related programs. Cluster controllers and programmable peripheral nodes also contain storage space.

When VTAM supports telecommunication services for your system, VTAM must use storage to build control blocks to keep track of sessions, blocks of data, and other information. If your system needs exceed your storage capacity, you might experience degraded response times. Similarly, an NCP can exceed its storage capacity if it receives more data from other parts of the network than it can send out.

The amount of storage required for tables and buffer pools depends on the number of major nodes being defined and the number of sessions required by application programs. By increasing VTAM efficiency, you can free storage for other uses.