SL_CALL_ANSWER_REQ primitive

Purpose

Request to accept a previously notified incoming call.

Requirement

Mandatory for common channel signaling processes. The primitive is not used for exchange data link signaling processes.

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_answer_request_st {
                      size_t sizetLength;
                      SL_CALL_REF slCallReference;
                      int iChannelNo;
                      int iVpackNo;
                      SL_APPL_INFO_ST slApplInfo;
                } call_answer_request_st;
...
} SL_REQUEST_PARM_ST;

Description

The SL_CALL_ANSWER_REQ primitive is sent by the channel process to the signaling process. This primitive accepts an incoming call, which the signaling process had previously notified to Blueworx Voice Response by sending an SL_CALL_SETUP_IND primitive. On receipt of the SL_CALL_ANSWER_REQ primitive the signaling process accepts the specified call, by signaling to the network. After the call has been connected, the signaling process sends the SL_CALL_ANSWER_CNF primitive to Blueworx Voice Response.

Corresponding state table action

The SL_CALL_ANSWER_REQ primitive and the matching SL_CALL_ANSWER_CNF, correspond to the AnswerCall state table action. 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. This 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 will be allocated by Blueworx Voice Response, and is available to the sender on return from sl_send_request(). The field will be 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_ANSWER_CNF primitive. Because the process id of the channel process is also required when sending SL_CALL_TERMINATE_IND, the signaling process should store this value together with the call reference for later use.
Command.id: The primitive that the structure contains. Must be set to SL_CALL_ANSWER_REQ.
Parms.call_answer_request_st.sizetLength: Must be set to sizeof(struct _call_answer_request_st).
Parms.call_answer_request_st.slCallReference: The call reference of the call being accepted. This must be the call reference specified on the SL_CALL_SETUP_IND primitive.
Parms.call_answer_request_st.iChannelNo: Identifies the channel associated with the call.
Parms.call_answer_request_st.iVpackNo: Identifies the trunk associated with the call.
Parms.call_answer_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