• 4.13.1.  PDK_MAKECALL_BLK
• 4.13.2.  IC_MAKECALL_BLK

4.13.  gc_MakeCall( )

When using E-1 CAS or T-1 robbed bit line devices, the timeout parameter in the gc_MakeCall( ) function is supported when the mode parameter is set to either EV_SYNC or EV_ASYNC.

For ICAPI protocols (Springware only), when the mode parameter is set to EV_ASYNC, the timeout parameter overrides the time-out parameter ($13) value and the outbound number of ringback tones parameter ($1) in most protocol country dependent parameters (.cdp) files.

• If the timeout parameter is set to 0, then the time-out and ringback parameters in the .cdp file are used to set the time-out conditions.
• If the timeout parameter is set to a value larger than a protocol time-out value, a protocol time-out may occur first, which will cause the gc_MakeCall( ) function to fail. The protocol time-out is configured in the country dependent parameters (.cdp) file.
• If the timeout value is reached before the remote end answers the call, the application is notified of this condition and should respond as described in the gc_MakeCall( ) function description in the Global Call API Library Reference.
• If all timeout values are set to 0, no time-out condition will apply.

For PDK protocols, the time-out value used is determined by:

• The timeout parameter in the gc_MakeCall( ) function.
• The PSL_DefaultMakeCallTimeout parameter specified in the .cdp file if the timeout parameter in the gc_MakeCall( ) function is 0 and call analysis is not specified.
• The PSL_CallProgressMaxDialingTime parameter specified in the .cdp file if the timeout parameter in the gc_MakeCall( ) function is 0 and call analysis is specified.

NOTE:

PDK protocols do not use the outbound number of ringback tones to define the time-out.

If your T-1 robbed bit circuit is provisioned for Feature Group A, your application should call the gc_MakeCall( ) function with a null dial string.

If a protocol error occurs during dialing and the default call progress enabled governs, then an error code or an event is returned as described in the gc_MakeCall( ) function description in the Global Call API Library Reference. If call progress is disabled and a protocol error occurs during dialing, then a GCRV_BUSY result value or an EGC_BUSY error is returned.

For drop and insert applications, call progress is typically disabled to enable the application to complete the dialing sequence, listen for voice or ringback on the line, and:

• if ringback is detected, to transition to the Alerting state
• if voice is detected, to transition to the Connected (call answered) state and to implement voice cut-through immediately

This methodology enables the application to pass signaling from the remote end (outbound line) to the caller on the inbound line. If call progress is not disabled, then the GCEV_ALERTING event and the GCEV_ANSWERED event may be received from the outbound line for an unacceptable amount of time after the dialing sequence was completed. During this period of time, the caller could misinterpret the silence on the line as a disconnect or a failure, and then hang up and redial. For further information, see the tips for programming drop and insert applications in the Global Call API Programming Guide for your operating system.

In an E-1 environment, the GCEV_ALERTING event is generated when the equivalent of ringback is recognized. For almost all E-1 protocols, this is a required part of the protocol, so E-1 applications will receive the GCEV_ALERTING event by default.

In a T-1 environment, the GCEV_ALERTING event is generated when the ringback is recognized. However, not all inbound applications will generate a ringback tone; for example, the PDK US MF protocol has disabled ringback tone generation by default to minimize call setup time. (Detecting the ringback tone takes several tenths of a second.) If the outbound application does not wish to use the detection of the ringback tone to generate the GCEV_ALERTING event, the CDP_OUT_Send_Alerting_After_Dialing parameter in the pdk_us_mf_io.cdp file should be set to 1 (default is 0). That way, if call progress is enabled, GCEV_ALERTING is sent after dialing is initiated rather than when ringback is detected.

Since GCEV_ALERTING is an optional event triggered by the inbound side, all applications must be able to handle not receiving the GCEV_ALERTING event.

When the gc_MakeCall( ) function sets up a call, the default is to enable call analysis (call progress). To change the enabled call progress default when making a call on Springware boards, see Section 4.13.1.  PDK_MAKECALL_BLK for PDK protocols and Section 4.13.2.  IC_MAKECALL_BLK for ICAPI protocols. (These structures do not apply to DM3 boards, which use gc_SetParm( ) parameters to change call progress configuration as discussed in Section 3.2.1.  Call Analysis with DM3 Boards.)

4.13.1.  PDK_MAKECALL_BLK

For PDK protocols, when the gc_MakeCall( ) function sets up a call, the default is to enable call analysis (call progress). This default can be changed on a call basis by setting the flags parameter in the PDK_MAKECALL_BLK data structure. See Table 8.  PDK_MAKECALL_BLK Field Descriptions.

The PDK_MAKECALL_BLK structure contains information used by the gc_MakeCall( ) function when setting up a call. The structure is defined as follows:

typedef struct pdk_makecall_blk{  
   unsigned long         flags;  
   void                  *v_rfu_ptr;  
   unsigned long         ul_rfu[4];  
}PDK_MAKECALL_BLK;

Table 8.  PDK_MAKECALL_BLK Field Descriptions

Field	Description
flags	Controls call analysis and media type detection on a per call basis. The flags included are:   · NO_CALL_PROGRESS: Set to 0 to enable call analysis (default). Set to 1 to disable call analysis.   · MEDIA_TYPE_DETECT: Set to 0 to enable media type detection. Set to 1 to disable media type detection.
*v_rfu_ptr	Reserved for future use.
ul_rfu[4]	Reserved for future use.

4.13.2.  IC_MAKECALL_BLK

For ICAPI protocols, when the gc_MakeCall( ) function sets up a call, the default is to enable call analysis (call progress). This default can be changed on a call basis by setting the flags parameter in the IC_MAKECALL_BLK data structure. See Table 9.  IC_MAKECALL_BLK Field Descriptions.

The IC_MAKECALL_BLK structure contains information used by the gc_MakeCall( ) function when setting up a call. The structure is defined as follows:

typedef struct ic_makecall_blk{  
   unsigned long         flags;  
   void                  *v_rfu_ptr;  
   unsigned long         ul_rfu[4];  
}IC_MAKECALL_BLK;

Table 9.  IC_MAKECALL_BLK Field Descriptions

Field	Description
flags	Controls call analysis and media type detection on a per call basis. The flags included are:   · NO_CALL_PROGRESS: Set to 0 to enable call analysis (default). Set to 1 to disable call analysis.
*v_rfu_ptr	Reserved for future use.
ul_rfu[4]	Reserved for future use.

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