Determining VTAM buffer pool values

Provide the VTAM® system programmer with IMS input and output message sizes. The values you select for the number and size of receive-any buffers, as specified on the RECANY keyword of the COMM macro, are of special importance.

You must specify the largest number of receive-any buffers that are required in order to support the VTAM network. You can override the size with the execution parameter, RECASZ, and the number with the execution parameter, RECANY. Session initiation fails for terminals that are added to the system if they require a larger receive-any buffer size than the size that is currently specified. You must restart the IMS system, specifying the increased buffer size, before the terminal can establish a session with IMS.