SL_CALL_TERMINATE_REQ primitive

Purpose

Request the clearing of an active call.

Requirement

Mandatory for common channel signaling processes. The primitive is used only by exchange data link signaling processes that have registered with transfer capability (see SL_SIGPROC_CAPABILITY_TRANSFER).

Library

The signaling interface library (libsl.a).

C syntax

typedef struct {
                SL_ID id;
                int iseq_no;
                pid_t pidCHP;
                SL_PRIMITIVE_TYPE Command;
                SL_REQUEST_PARM_ST Parms;
} SL_REQUEST_ST;
...
typedef union {
...
                struct _call_terminate_request_st {
                    size_t sizetLength;
                    SL_CALL_REF slCallReference;
                    int iChannelNo;
                    int iVpackNo;
                    SL_APPL_INFO_ST slApplInfo;
                } call_terminate_request_st;
...
} SL_REQUEST_PARM_ST;

Description

The SL_CALL_TERMINATE_REQ primitive is sent by the channel process to the signaling process to request to terminate or clear an active call. The channel process clears a call by sending the SL_CALL_TERMINATE_REQ primitive to the signaling process. The signaling process clears the call to the network. When the call has been cleared, the signaling process sends back the SL_CALL_TERMINATE_CNF primitive. When the SL_CALL_TERMINATE_CNF primitive has been received by Blueworx Voice Response, the voice channel is disconnected and the call is in the idle state.

The signaling process must always clear a call upon request.

The SL_CALL_TERMINATE_REQ primitive can also signify the completion of an earlier call transfer request (see Call transfer model).

An exchange data link should use this request to complete any pending call transfer requests, if necessary, before sending back the SL_CALL_TERMINATE_CNF primitive. If the transfer request can be completed by allowing the CAS signaling to perform a hangup, then the signaling process can send back the SL_CALL_TERMINATE_CNF immediately with a reply code of SL_REPLY_SUCCESS.

If there is no pending transfer request, then the SL_CALL_TERMINATE_CNF can be returned immediately with a reply code of SL_REPLY_SUCCESS.

Corresponding state table action

The SL_CALL_TERMINATE_REQ primitive and the matching SL_CALL_TERMINATE_CNF correspond to the TerminateCall or CloseEverything state table actions. See the Blueworx Voice Response for AIX: Application Development using State Tables information.

Parameters

id: Eye-catcher that identifies the structure as containing a request primitive. Must be set to SLID_REQUEST_ST.
iseq_no: The sequence number of the primitive. This field must be set to 0 when the primitive is sent to Blueworx Voice Response; the actual sequence number is allocated by Blueworx Voice Response, and is available to the sender on return from sl_send_request(). The field is set when the primitive is received from Blueworx Voice Response by the signaling process.
pidCHP: The process id of the channel process. The signaling process should use this value to set the pidCHP field of the corresponding SL_CALL_TERMINATE_CNF primitive.
Command.id: The primitive that the structure contains. Must be set to SL_CALL_TERMINATE_REQ.
Parms.call_terminate_request_st.sizetLength: Must be set to sizeof(struct _call_terminate_request_st).
Parms.call_terminate_request_st.slCallReference: The call reference that identifies the call to be cleared. This field must be set to a call reference allocated by Blueworx Voice Response for a previous SL_CALL_SETUP_REQ, or SL_CALL_SETUP_IND primitive.
Parms.call_terminate_request_st.iChannelNo: Identifies the channel associated with the call.
Parms.call_terminate_request_st.iVpackNo: Identifies the trunk associated with the call.
Parms.call_terminate_request_st.slApplInfo: Contains both the length of the call information tag string (including the null terminator '\0') and the call information tag string array itself. The string is used to pass information between state tables and the signaling process. For more information see SL_APPL_INFO_ST data structure