Storage definitions
TCP/IP uses several types of storage.
- common storage
- Common storage is shared across the whole system and can be accessed from any address space. Common storage is managed by the Virtual Storage Management component of the z/OS® operating system. TCP/IP's usage of common storage for the most part is for ECSA (extended common service area).
- private storage
- Private storage is storage that is unique to an address space. Private storage is also referred to as pool storage.
- CSM
- Communication Storage Manager (CSM) enables TCP/IP, VTAM®, and other applications to use CSM buffers
to reduce data movement. CSM interfaces with the z/OS operating system to provide the storage
buffers. Buffers are maintained in both common storage and in the
CSM data spaces. The application (for example TCP/IP) has the option
of requesting the buffers from common storage or the CSM data spaces.
The storage is managed in pools of the following predefined buffer
sizes:
- 4 KB
- 16 KB
- 32 KB
- 60 KB
- 180 KB
See z/OS Communications Server: CSM Guide for additional information relating to the CSM component.