Technical data

isdnio(7I) Ioctl Requests SunOS 5.5
Channel
Management
IOCTLS
The following ioctls describe operations on individualchannels and the connection of
multiple channels.
ISDN_SET_FORMAT
fd is a data channel, the management pseudo-channel associated with the data
channel, or the management channel associated with the data channel’s interface
or controller. arg is a pointer to a struct isdn_format_req. The
ISDN_SET_FORMAT ioctl sets the format of an ISDN channel-stream datapath. It
may be issued on both an open ISDN channel-stream datapath Stream or an
ISDN Management Stream. Note that an open(2) call for a channel-stream data-
path will fail if anISDN_SET_FORMAT has never been issued after a reset, as the
mode for all channel-stream datapaths is initiallybiased to
ISDN_MODE_NOTSPEC. arg is a pointer to an ISDN format type
(isdn_format_req_t∗).
typedef struct isdn_format_req {
isdn_chan_t channel;
isdn_format_t format; /∗ data format ∗/
int reserved[4]; /∗ future use - must be 0 ∗/
} isdn_format_req_t;
If there is not an open channel-stream datapath for a requested channel, the
default format of that channel will be set for a subsequent open(2).
To modify the format of an open STREAM, the driver will disconnect the
hardware channel, flush the internal hardware queues, set the new default
configuration, and finallyreconnect the data path using the newly specified for-
mat. Upon taking effect, all state information will be reset to initial conditions, as
if a channel was just opened. It is suggested that the user flush the interface as
well as consult the hardware specific documentation to insure data integrity.
If a user desires to connect more than one B channel, such as an H-channel, the
B-channel with the smallest offset should be specified, then the precision should
be specified multiples of 8.
For an H-channel the precision value would be 16. The user should subsequently
open the base B-channel. If any of the sequential B-channels are busy the open
will fail, otherwise all of the B-channels that are to be used in conjunction will be
marked as busy.
The returned failure codes and their descriptions are listed below:
EPERM /∗ No permission for intented operation ∗/
EINVAL /∗ Invalid format request ∗/
EIO /∗ Set format attempt failed. ∗/
ISDN_SET_CHANNEL
The ISDN_SET_CHANNEL ioctl sets up a data connection within an ISDN con-
troller. The ISDN_SET_CHANNEL ioctl can only be issued from an ISDN manage-
ment stream to establish or modify channel-channel datapaths. The ioctl
7I-162 modified 7 Apr 1994