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AIX Version 4 Files Reference

mpqi Special File

Purpose

Provides access to the Multiport Model 2 Adapter (MM2) device driver via SNA Services, GDLC, or user-written applications compatible with current MPQP Applications Programming Interface (API).

Description

The Multiport Model 2 devic e driver provides access to the mpqi special file through SNA Services, Generic Data Link Control, or through user-written applications.

Usage Considerations

When accessing the Multiport Model 2 device driver via these methods, consider the following information:

Driver Initialization and Termination

The device driver can be loaded and unloaded in the kernel in the same way as other communications device drivers. The device driver supports the configuration calls to initialize and terminate itself. Therefore, you must ensure that the device driver is initialized before using it. A listing of the device driver, either via SMIT or by using the lsdev command, should indicate the device driver state as Available.

Special File Support

The Multiport Model 2 device driver is a character I/O device and provides a special file entry in the /dev directory for file system access. The Multiport Model 2 device driver uses the t_start_dev and t_chg_parms structures defined in the /usr/include/sys/mpqp.h file to preserve compatibility with the existing GDLC, MPQP API and SNA Services interface. However, only a subset of the #define values is supported for the following t_start_dev structure fields:

data_proto Identifies the data protocol. T he Multiport Model 2 device driver supports the SDLC DATA_PRO_SDLC_HDX value (indicating half duplex only) and the bisync DATA_PRO_BSC value. Bisync support is offered only in AIX Versions 4.2 and later.
baud_rate Specifies the baud rate for transmit and receive clock. The Multiport Model 2 device driver only supports external clocking where the modem supplies the clock, and this field should be set to zero. However, when using SNA Services, this field is ignored when external clocking is specified in the physical link profile and does not need to be zero.

Related Information

Special Files Overview

MPQP Device Handler Interface Overview in AIX Version 4.3 Kernel Extensions and Device Support Programming Concepts

Data Link Control in AIX Version 4.3 Technical Reference: Communications Volume 1


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