Network Card User Manual

Appendix C Application Programmer’s Interface 89
Q.93B Driver Interface
The signalling API, called Q.2931 Call Control (qcc), consists of two sets of similar
functions: one for applications running in the kernel and one for applications
running in user space. Each set provides functions to build and parse Q.2931
signalling messages, which are required to set up and tear down connections.
One additional function assists applications in establishing appropriate connections
to the Q.93B driver. q_ioc_bind associates a service access point (SAP) with the
specified connection to the Q.93B driver. The driver uses the SAP to direct incoming
messages to applications.
Establishing a Connection to the Q.93B Driver
Use the open(2) system call to obtain a file descriptor to the driver. After opening
the driver, q_ioc_bind should be called, associating in the Q.93B driver a service
access point (SAP) with this application. Finally, if the application is a kernel driver,
it should be linked above the Q.93B driver, using the I_LINK or I_PLINK ioctl (refer
to the streamio(7) man page for information about this ioctl).