SCO ISDN adapter drivers

ISDN I/O controls (ioctls)

ISDN drivers use MDI ioctl system calls for communications between the driver and applications such as dialers and port monitors. MDI ioctl usage in ISDN drivers depends on whether the ioctls:

are used in both LAN and ISDN drivers; note that some ioctls may evoke dissimilar responses in these two driver types
are only used in ISDN drivers

SCO ISDN-specific ioctls are implementations of CAPI ``operations'':

CAPI operation MDI/ISDN ioctl

CAPI_REGISTER ISDN_REGISTER

CAPI_RELEASE ISDN_RELEASE

CAPI_GET_PROFILE ISDN_GETPROFILE

CAPI operation	MDI/ISDN ioctl
CAPI_REGISTER	ISDN_REGISTER
CAPI_RELEASE	ISDN_RELEASE
CAPI_GET_PROFILE	ISDN_GETPROFILE

Applications can ``register'' with the SCO ISDN interface by opening the /dev/netx device and issuing the ISDN_REGISTER ioctl downstream with the relevant parameters to the opened device.

NOTE: For ISDN drivers, the SCO implementation differs from the standard CAPI UNIX implementation. In the CAPI UNIX implementation, the Stream itself is used to identify the applications. Because SCO ISDN handles multiple communications over a single Stream to the MDI/ISDN driver, the application ID must be used to to identify the target ISDN application in the SCO ISDN implementation.

It is the DLPI (Data Link Provider Interface) module that, upon receiving the register ioctl, requests an application ID from the ISDN driver. The DLPI module then maintains the mapping of application ID to Stream. The application itself does not need to known the application ID.

When the /dev/netx device used by the ISDN adapter is closed, the driver must respond to a ISDN_RELEASE ioctl issued by the DLPI module.

The ISDN_GETPROFILE ioctl gets ``profile'' information about the ISDN device: number of controllers, controller features, and supported protocols.

The values of the defined ioctls and the parameter structures are defined in the <sys/scoisdn.h> header file.