NIO CommKit Host Interface Installation and System Administration Manual

DKUX(7) DKUX(7)
E-90 CommKit Host Interface, Release 4.0
NAME
dkux – CommKit Host Interface call processing module
DESCRIPTION
dkux is a STREAMS module that provides call processing support for the host interfaces by communicating
with peer processes in the AT&T data switch controller via the dkhs(7) driver. Call processing and
initialization are accomplished by means of messages passed between the data switch controller and the host,
the format and content of which are defined by the UNIXP protocol. dkux contains an implementation of the
UNIXP protocol.
dkux performs bookkeeping functions relating to the status of data switch circuits on each interface. It must
also continually exchange special messages with the controller to inform the controller that the host is active.
To ensure that dkux is always present, the dkdaemon(1M) process started when entering init state 2 by the
dkitrc(1M) script opens the Stream associated with the Common Signaling Channel device and pushes and
holds the dkux module on the Stream. The interface remains active as long as the dkdaemon(1M) keeps dkux
pushed on the Common Signaling Channel.
There are also functions performed by dkux , such as call setup, which are required on an as-needed basis.
To this end, the dkux module may be pushed on any Stream associated with a data switch circuit.
Read-side Behavior
The following STREAMS messages are acted on by the dkux module when received from downstream:
M_CTL Supervisory interactions between this module and the dkhs(7) driver take place via
commands contained in M_CTL messages. These messages are processed when received
from downstream on the Stream associated with the Common Signaling Channel. On other
channels, they are passed upstream uninterpreted.
M_DATA Messages received from the data switch controller arrive on the Common Signaling
Channel packaged in M_DATA messages. dkux processes these messages according to the
UNIXP protocol. M_DATA messages received on other channels are passed upstream
uninterpreted.
M_FLUSH Standard STREAMS processing for M_FLUSH messages is supported in the dkux module.
Messages of all other types are passed upstream uninterpreted.
The following STREAMS messages are generated by the dkux module and sent upstream:
M_IOCACK All recognized and successfully processed M_IOCTL messages are positively acknowledged
with an upstream M_IOCACK message.
M_IOCNAK All recognized but rejected M_IOCTL requests are negatively acknowledged with upstream
M_IOCNAK messages.
Write-side Behavior
The following STREAMS messages are recognized and processed by the dkux module when received from
upstream:
M_IOCTL A number of commands may be sent from user-level to the driver in the form of M_IOCTL
messages.
M_FLUSH Standard STREAMS processing for M_FLUSH messages is supported in the dkux module.
The following message types are generated by dkux and are sent downstream.
M_CTL Supervisory circuit control information is passed down to the dkhs(7) driver in M_CTL
messages. These messages are sent downstream on the Stream associated with the Common
Signaling Channel.