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Tablec3 qcc functions, Call setup – Sun Microsystems 3U User Manual

Page 115

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Appendix C

Application Programmer’s Interface

93

Call Setup

To make a call, send a SETUP message down to Q.93B and wait for a SETUP_ACK
from Q.93B. The SETUP message should include a Broadband Higher Layer
Information (BHLI) information element that contains a four-octet SAP identified as
User Specific Information. The SAP is used to identify the application on the
receiving host to which the Q.93B should direct the message. After receiving a
SETUP_ACK with a 0 error field, wait for a CALL_PROCEEDING, ALERTING,

TABLE C-3

qcc

Functions

Name

Functionality

Input

Output

qcc_bld_*

Creates and encodes a message;
enables customization of a limited
set of values, depending on the
message type. Configurable values
are passed in as parameters.

Parameter values

Encoded Q.2931
message (in the format
shown in

FIGURE C-2

)

qcc_parse_*

Extracts a defined set of values
from an encoded message

Encoded Q.2931 message
(in the format shown in

FIGURE C-2

)

Parameter values

qcc_len_*

Returns the maximum length of the
buffer that should be allocated for
the second strbuf in a Q.2931
message. Only applicable to user
space applications; the kernel API
allocates the buffers inside the

qcc_bld/qcc_pack

functions.

none

Maximum length of
the message

qcc_create_*

Creates a message structure with
the required values set. You can
further customize the structure
using

qcc_set_ie

.

Default parameter values

Message structure
(defined in

)

qcc_set_ie

Updates or inserts values for an
information element into a message
structure.

Message structure and IE
structure (defined in

)

Updated message
structure

qcc_pack_*

Takes a message structure and
encodes it into an actual Q.2931
message, consisting of the two
mblks (or strbufs) illustrated in

FIGURE C-2

.

Message structure (defined
in

)

Encoded Q.2931
message (in the format
shown in

FIGURE C-2

)

qcc_unpack_*

The reverse of

qcc_pack_*

: takes

an encoded message and decodes
the data into a message structure.

Encoded Q.2931 message
(in the format shown in

FIGURE C-2

)

Message structure
(defined in

)