QIO Configuration and Management Manual

QIO Configuration and Management Manual—424717-008
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1 Introduction to QIO
This section describes the architecture and functions of the QIO subsystem.
The QIO subsystem improves I/O performance by providing efficient sharing of
processor memory for the following processes:

SLSA (ServerNet LAN Systems Access) subsystem

SWAN (ServerNet wide area network) concentrator

NonStop TCP/IP, NonStop TCP/IPv6, and Parallel Library TCP/IP

NonStop IPX/SPX

Expand/IP line-handler
QIO provides this function by providing a shared data segment and associated
functions to manage the various resources of the shared segment.
The QIO subsystem consists of the following components:

QIOMON process per processor

QIO memory segment

QIO library

QIO drivers and interrupt handlers