8. Application Guidelines
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Each BRI structure is composed of one D channel and two B (bearer) channels. A
BRI board device, such as briS1, is defined as a station and controls the D channel
the same way as a PRI board device. A BRI time slot device, such as briS1T1, is
defined as a bearer channel under a station and is handled the same way as a PRI
line device.
NOTE:
For BRI, the protocol must be configured at initialization using the
cc_SetDChanCfg( ) function. See Section 8.4.1. BRI/SC Configuration
below and the cc_SetDChanCfg( ) function description in Chapter
5. ISDN Function Reference for more information.
8.3.2. MAKECALL Block Initialization and Settings
Because ISDN services vary with switches and provisioning plans, a set of default
standards cannot be set for the MAKECALL_BLK. Therefore, it is up to the user
application to fill in the applicable MAKECALL_BLK values that apply to the
particular provisioning.
The current ISDN Call Control library will check for the ISDN_NOTUSED
(0xFF) define to determine
which Information Elements (IEs) to send down to the firmware
the length of each IE to be sent
All of the bearer capability elements in the MAKECALL_BLK structure must be
specified or the ISDN library will not properly fill in the ISDN_CMD messages to
pass down to the firmware. It is suggested that the application first initialize the
MAKECALL_BLK structure with a set of defaults prior to filling in settings
pertaining to the particular ISDN service.
A sample MAKECALL_BLK initialization is shown below:
/* Initialize the MAKECALL block */
makecall_blk.isdn.BC_xfer_cap = BEAR_CAP_SPEECH;
makecall_blk.isdn.BC_xfer_mode = ISDN_ITM_CIRCUIT;
makecall_blk.isdn.BC_xfer_rate = BEAR_RATE_64KBPS;
makecall_blk.isdn.usrinfo_layer1_protocol = 0xFF;
makecall_blk.isdn.usr_rate = 0xFF;
makecall_blk.isdn.destination_number_type = 0xFF;
makecall_blk.isdn.destination_number_plan =0xFF;
makecall_blk.isdn.destination_sub_number_type = 0xFF;
makecall_blk.isdn.destination_sub_phone_number[0] = NULL;
makecall_blk.isdn.origination_number_type = 0xFF;
makecall_blk.isdn.origination_number_plan = 0xFF;