7. ISDN Events and Errors

7.1.1. Termination Events
7.1.2. Unsolicited Events

7.1. Event Categories

This chapter describes the events and error/cause codes that are returned by the Dialogic ISDN library functions. The function descriptions in Chapter 5. ISDN Function Reference list the possible error codes and, for asynchronous functions, the termination events returned by the function.

There are two types of events returned by the ISDN library functions: those that are returned after the termination of a function call and those that are unsolicited and triggered by external events.

7.1.1. Termination Events

Table 47 lists the events returned at the termination of asynchronous function calls. The events are categorized by call reference number (CRN) referenced functions, line device handle referenced functions, and CRN or line device handle referenced functions. (See Section 5.3. Function References: CRNs, CRVs, and Line Device Handles for more on function references.)

NOTE:: Termination events are solicited events that are returned by asynchronous functions only.

Table 47. Termination Events

Termination Event

Returned After:

Indicates:

Refer-ence:

CCEV_ACCEPT

cc_AcceptCall( )

ALERTING message has been sent to the network.

CRN

CCEV_ANSWERED

cc_AnswerCall( )

CONNECT message has been sent to the network.

CRN

CCEV_CONNECTED

cc_MakeCall( )

CONNECT message has been received from the network.

CRN

CCEV_DROPCALL

cc_DropCall( )

DISCONNECT message has been sent to the network.

CRN

CCEV_HOLDACK

cc_HoldCall( )

A HOLD CALL COMPLETED acknowledge message was received by the application (that is, a hold call request was acknowledged by remote equipment, and the call is in HOLD state).

CRN

CCEV_HOLDREJ

cc_HoldCall( )

A HOLD CALL REJECT message was received from remote equipment (that is, a call from remote equipment did not enter HOLD state).
Use the cc_GetCallInfo( ) function to retrieve information about why the request was rejected.

CRN

CCEV_MOREDIGITS

cc_GetMoreDigits( )

Requested number of digits has been received. Use cc_GetDNIS( ) to retrieve digits.

CRN

CCEV_OFFERED

cc_WaitCall( )

SETUP message has been received. Use cc_GetCallInfo( ) to retrieve information about the event.

CRN

CCEV_PLAYTONE

cc_PlayTone( )

User-defined tone successfully played.

Line Device Handle

CCEV_PLAYTONEFAIL

Failure of cc_PlayTone( )

Request to play user-defined tone failed.

Line Device Handle

CCEV_RELEASECALL

cc_ReleaseCallEx( )

Dialogic ISDN resources were successfully released for the call.

CRN

CCEV_RELEASECALLFAIL

Failure of cc_ReleaseCallEx( )

The request to release the resources for the call failed.

CRN

CCEV_REQANI

cc_ReqANI( )

ANI has been received from the network. Used only with the AT&T ANI-on-demand feature.

CRN

CCEV_RESTART

cc_Restart( )

Restart operation has been completed. The channel is in NULL state.

Line Device Handle

CCEV_RESTARTFAIL

Failure of cc_Restart( )

Typically, this event is triggered by an incorrect state of a line device. The application may use cc_ResultValue( ) after this event is received to verify the reason for failure.

Line Device Handle

CCEV_RETRIEVEACK

cc_RetrieveCall( )

A RETRIEVE CALL COMPLETE acknowledge message was received from the network. The indicated network has reconnected a held call to a B channel.

CRN

CCEV_RETRIEVEREJ

cc_RetrieveCall( )

A RETRIEVE CALL REJECT message was received from the network. The indicated network has rejected a request to reconnect a held call to a B channel.
This event can be received only when the application acts as terminal equipment.
Use the cc_GetCallInfo( ) function to retrieve information about why the request was rejected.

CRN

CCEV_SETBILLING

cc_SetBilling( )

Billing information for the call has been acknowledged by the network. This event is used only with the AT&T Vari-A-Bill feature.

CRN

CCEV_ SETCHANSTATE

cc_SetChanState( )

The B channel is placed in the requested state.

Line Device Handle

CCEV_STOPTONE

cc_StopTone( )

The tone operation was terminated.

Line Device Handle

CCEV_STOPTONEFAIL

Failure of cc_StopTone( )

The request to terminate the playing of a tone failed.

Line Device Handle

CCEV_TASKFAIL

A request or message from the application is rejected by the firmware.

Rejection of a request or message. Normally, this event is triggered by an incorrect function call during the call. This event can also be received due to "race conditions," meaning that the application and the network requested different actions from the firmware at the same time. The application may use cc_Restart( ) after this event is received to reset the channel.

CRN or Line Device Handle

CCEV_TONEREDEFINE

cc_ToneRedefine( )

The tone(s) in the firmware tone template table were successfully redefined.

Line Device Handle

CCEV_TONEREDEFINEFAIL

Failure of cc_ToneRedefine( )

The request to redefine tone(s) in the firmware tone template table failed.

Line Device Handle

7.1.2. Unsolicited Events

Table 48 lists the events that are triggered by external signals. Events triggered by external signals are unsolicited events that are returned by both asynchronous and synchronous functions.

Table 48. Unsolicited Events

External Event

Indicates:

CCEV_ALERTING

An ALERTING message has been received by the application, indicating that the connection request has been accepted by the network. By default, the firmware will report this event. The application may clear the CCMSK_ALERT bit to block this event.

CCEV_CALLINFO

An INFORMATION message has been received by the application, for example, in response to a cc_SndMsg( ) function call in which the msg_type specified is SndMsg_Information.
Use the cc_GetCallInfo( ) function to retrieve information about the event.

CCEV_CONFDROP

A DROP request has been received; the request was made by sending the SndMsg_Drop message type via the cc_SndMsg( ) function.
The CCEV_CONFDROP event has two different meanings that depend upon the type of call:
Two-party call - the event is a request to disconnect the call. The application should respond by issuing a cc_DropCall( ).
Conference call - the event is a request to remove the last party that was added to the conference. The application needs to respond to this request with either a SndMsg_DropAck or SndMsg_DropRej message to indicate the acceptance or rejection of the request. If the request is accepted, the party is dropped from the conference.
The CCEV_CONFDROP event only pertains to a Custom BRI 5ESS switch type.

CCEV_CONGESTION

A CONGESTION message has been received by the application, indicating that the remote end is not ready to accept incoming user information.
Use the cc_GetCallInfo( ) function to retrieve additional information about the event.

CCEV_D_CHAN_STATUS

The D channel status was changed as a result of the event on the D channel.
Refer to the sample code in the cc_GetSAPI( ) and cc_GetCES( ) function descriptions for more information.

CCEV_DISCONNECTED

A DISCONNECT, RELEASE COMPLETE, or RELEASE message has been received by the application. This event may be received in any state except IDLE, DISCONNECTED, or NULL. The application must send a cc_DropCall( ) after this event is received.
Use the cc_GetCallInfo( ) function to retrieve additional information about the event.

CCEV_DIVERTED

NAM with divert information has been received by the application. An outgoing call has been successfully diverted to another station.

CCEV_DROPACK

The network has honored a DROP request for a conference call; the request was made by sending the SndMsg_Drop message type via the cc_SndMsg( ) function. The event is sent on the corresponding line device.
The CCEV_DROPACK event pertains only to a Custom BRI 5ESS switch type.

CCEV_DROPREJ

The network has not honored a DROP request for a conference call. The event is sent on the corresponding line device.
The CCEV_DROPREJ event pertains only to a Custom BRI 5ESS switch type.

CCEV_ FACILITY

A FACILITY REQUEST message has been received by the application.

CCEV_FACILITYACK

A FACILITY_ACK message has been received by the application.

CCEV_FACILITYGLOBAL

An ISDN_FACILITY message containing a Global CRN value was received. This event is sent on the board level device, as the event is associated with all calls on the device.
Upon receipt of this event, the application may issue a cc_GetNonCallMsg( ) function to retrieve the data into its local structure.

CCEV_FACILITYNULL

An ISDN_FACILITY message was received containing a Dummy (NULL) CRN.
Upon receipt of this event, the application may issue a cc_GetNonCallMsg( ) function to retrieve the data into its local structure.

CCEV_FACILITYREJ

A FACILITY_REJ message has been received by the application.

CCEV_HOLDCALL

A HOLD message was received from remote equipment. The application may send cc_HoldAck( ) or cc_HoldRej( ) as a response.

CCEV_INFOGLOBAL

An ISDN_INFORMATION message containing a Global CRN value was received. This event is sent on the board level device, as the event is associated with all calls on the device.
Upon receipt of this event, the application may issue a cc_GetNonCallMsg( ) function to retrieve the data into its local structure.

CCEV_INFONULL

An ISDN_INFORMATION message was received containing a NULL CRN.
Upon receipt of this event, the application may issue a cc_GetNonCallMsg( ) function to retrieve the data into its local structure.

CCEV_L2FRAME

A data link layer frame has been received by the application. The application should use the cc_GetFrame( ) function to retrieve the received frame. It is the application's responsibility to analyze the contents of the frame.

CCEV_L2NOBFFR

There are no buffers available to save the incoming frame.

CCEV_NOFACILITYBUF

There are no buffers available to store the Network Facility Information Element (IE). This event can be ignored. The event is received for every incoming ISDN message that contains the Network Facility IE. The IE can be retrieved using the cc_GetInfoElem( ) function or the cc_GetCallInfo(U_IES) function.

CCEV_NOTIFY

A NOTIFY message has been received by the application.
Use the cc_GetCallInfo( ) function to retrieve additional information about the event.

CCEV_NOTIFYGLOBAL

An ISDN_NOTIFY message containing a Global CRN value was received. This event is sent on the board level device, as the event is associated with all calls on the device.
Upon receipt of this event, the application may issue a cc_GetNonCallMsg( ) function to retrieve the data into its local structure.

CCEV_NOTIFYNULL

An ISDN_NOTIFY message was received containing a Dummy (NULL) CRN.
Upon receipt of this event, the application may issue a cc_GetNonCallMsg( ) function to retrieve the data into its local structure.

CCEV_NSI (DPNSS and Q.SIG only)

A Network Specific Indication (NSI) message was received from the network. The application should use cc_GetCallInfo( ) to retrieve the NSI string(s).

CCEV_ISDNMSG

An undefined ISDN message has been received by the application.

CCEV_PROCEEDING

An ISDN message has been received by the application. By default, the firmware will send this event to the application. The application may clear the CCMSK_PROCEEDING bit to block this event.

CCEV_PROGRESSING

A PROGRESS message has been received by the application. By default, the firmware will send this event to the application. The application may block this event by clearing the CCMSK_PROGRESS bit.
Use the cc_GetCallInfo( ) function to retrieve additional information about the event.

CCEV_RCVTERMREG_ACK

The acceptance, by the switch, of a terminal initialization request from a station that has been configured as a North American User side (TE) station. This event occurs on a board level device, not a channel device.
Use the USPID_BLK data structure to retrieve information about the event.

CCEV_RCVTERMREG_NACK

The rejection, by the switch, of a terminal initialization request from a station that has been configured as a North American User side (TE) station. This event occurs on a board level device, not a channel device.
Use the TERM_NACK_BLK data structure to retrieve information about the event.

CCEV_REDIRECT

The firmware has reset its call state to Overlap Sending. The request to redirect was made by the switch to solicit more out-of-band digits.
The CCEV_REDIRECT event pertains only to a Custom BRI 5ESS switch type configured as the TE (User side). A station configured as an NT (Network side) may generate a message, via the cc_SndMsg( ) function, causing this event.

CCEV_RETRIEVECALL

A RETRIEVE CALL acknowledge message was received from terminal equipment. The indicated terminal equipment requests reconnection of a call on hold.
This event can only be received by an application when the application acts as a network.

CCEV_SERVICE

A SERVICE message has been received from the network.

CCEV_SERVICEACK

A SERVICE ACKNOWLEDGE message has been received from the network.

CCEV_SETCHANSTATE

The B channel status was changed as a result of cc_SetChanState( ) or a network request.
This event occurs on a board level device, not a channel device.

CCEV_SETUP_ACK

A SETUP_ACK message has been received by the application.

CCEV_STATUS

A STATUS message has been received from the network.

CCEV_STATUS_ENQUIRY

A STATUS_ENQ message has been received from the network.

CCEV_TERM_REGISTER

An unsolicited event indicating that some action is required by the switch for the North American terminal initialization procedure. The application must respond to the event using the cc_TermRegisterResponse( ) function to either accept or reject the request to initialize the terminal.
A Service Profile Identifier (SPID) value is associated with the event. A SPID is assigned by a phone company to a Fully Initializing Terminal (FIT) on an ISDN Basic Rate Interface (BRI) line. This event occurs on a board level device, not on a channel device.
Use the SPID_BLK data structure to retrieve information about the event.

CCEV_TIMER

An unsolicited event indicating that a timer has expired.

CCEV_TRANSFERACK

A TRANSFER ACKNOWLEDGE MESSAGE was received from the network. The indicated network has accepted a request to transfer a call.

CCEV_TRANSFERREJ

A TRANSFER REJECT message was received from the network. The indicated network has rejected a request to transfer a call.

CCEV_TRANSIT (DPNSS and Q.SIG only)

After a transfer is established, transit messages are used for relating messages between the originating end and the terminating end.

CCEV_USRINFO

A USER INFORMATION message has been received by the application, indicating that a user-to-user information (UUI) event is coming. For example, this event is received in response to a cc_SndMsg( ) function call, from the far end, in which the msg_type is SndMsg_UsrInformation.
Use the cc_GetCallInfo( ) function to retrieve the UUI.

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Termination Event	Returned After:	Indicates:	Refer-ence:
CCEV_ACCEPT	cc_AcceptCall( )	ALERTING message has been sent to the network.	CRN
CCEV_ANSWERED	cc_AnswerCall( )	CONNECT message has been sent to the network.	CRN
CCEV_CONNECTED	cc_MakeCall( )	CONNECT message has been received from the network.	CRN
CCEV_DROPCALL	cc_DropCall( )	DISCONNECT message has been sent to the network.	CRN
CCEV_HOLDACK	cc_HoldCall( )	A HOLD CALL COMPLETED acknowledge message was received by the application (that is, a hold call request was acknowledged by remote equipment, and the call is in HOLD state).	CRN
CCEV_HOLDREJ	cc_HoldCall( )	A HOLD CALL REJECT message was received from remote equipment (that is, a call from remote equipment did not enter HOLD state). Use the cc_GetCallInfo( ) function to retrieve information about why the request was rejected.	CRN
CCEV_MOREDIGITS	cc_GetMoreDigits( )	Requested number of digits has been received. Use cc_GetDNIS( ) to retrieve digits.	CRN
CCEV_OFFERED	cc_WaitCall( )	SETUP message has been received. Use cc_GetCallInfo( ) to retrieve information about the event.	CRN
CCEV_PLAYTONE	cc_PlayTone( )	User-defined tone successfully played.	Line Device Handle
CCEV_PLAYTONEFAIL	Failure of cc_PlayTone( )	Request to play user-defined tone failed.	Line Device Handle
CCEV_RELEASECALL	cc_ReleaseCallEx( )	Dialogic ISDN resources were successfully released for the call.	CRN
CCEV_RELEASECALLFAIL	Failure of cc_ReleaseCallEx( )	The request to release the resources for the call failed.	CRN
CCEV_REQANI	cc_ReqANI( )	ANI has been received from the network. Used only with the AT&T ANI-on-demand feature.	CRN
CCEV_RESTART	cc_Restart( )	Restart operation has been completed. The channel is in NULL state.	Line Device Handle
CCEV_RESTARTFAIL	Failure of cc_Restart( )	Typically, this event is triggered by an incorrect state of a line device. The application may use cc_ResultValue( ) after this event is received to verify the reason for failure.	Line Device Handle
CCEV_RETRIEVEACK	cc_RetrieveCall( )	A RETRIEVE CALL COMPLETE acknowledge message was received from the network. The indicated network has reconnected a held call to a B channel.	CRN
CCEV_RETRIEVEREJ	cc_RetrieveCall( )	A RETRIEVE CALL REJECT message was received from the network. The indicated network has rejected a request to reconnect a held call to a B channel. This event can be received only when the application acts as terminal equipment. Use the cc_GetCallInfo( ) function to retrieve information about why the request was rejected.	CRN
CCEV_SETBILLING	cc_SetBilling( )	Billing information for the call has been acknowledged by the network. This event is used only with the AT&T Vari-A-Bill feature.	CRN
CCEV_ SETCHANSTATE	cc_SetChanState( )	The B channel is placed in the requested state.	Line Device Handle
CCEV_STOPTONE	cc_StopTone( )	The tone operation was terminated.	Line Device Handle
CCEV_STOPTONEFAIL	Failure of cc_StopTone( )	The request to terminate the playing of a tone failed.	Line Device Handle
CCEV_TASKFAIL	A request or message from the application is rejected by the firmware.	Rejection of a request or message. Normally, this event is triggered by an incorrect function call during the call. This event can also be received due to "race conditions," meaning that the application and the network requested different actions from the firmware at the same time. The application may use cc_Restart( ) after this event is received to reset the channel.	CRN or Line Device Handle
CCEV_TONEREDEFINE	cc_ToneRedefine( )	The tone(s) in the firmware tone template table were successfully redefined.	Line Device Handle
CCEV_TONEREDEFINEFAIL	Failure of cc_ToneRedefine( )	The request to redefine tone(s) in the firmware tone template table failed.	Line Device Handle

External Event	Indicates:
CCEV_ALERTING	An ALERTING message has been received by the application, indicating that the connection request has been accepted by the network. By default, the firmware will report this event. The application may clear the CCMSK_ALERT bit to block this event.
CCEV_CALLINFO	An INFORMATION message has been received by the application, for example, in response to a cc_SndMsg( ) function call in which the msg_type specified is SndMsg_Information. Use the cc_GetCallInfo( ) function to retrieve information about the event.
CCEV_CONFDROP	A DROP request has been received; the request was made by sending the SndMsg_Drop message type via the cc_SndMsg( ) function. The CCEV_CONFDROP event has two different meanings that depend upon the type of call: Two-party call - the event is a request to disconnect the call. The application should respond by issuing a cc_DropCall( ). Conference call - the event is a request to remove the last party that was added to the conference. The application needs to respond to this request with either a SndMsg_DropAck or SndMsg_DropRej message to indicate the acceptance or rejection of the request. If the request is accepted, the party is dropped from the conference. The CCEV_CONFDROP event only pertains to a Custom BRI 5ESS switch type.
CCEV_CONGESTION	A CONGESTION message has been received by the application, indicating that the remote end is not ready to accept incoming user information. Use the cc_GetCallInfo( ) function to retrieve additional information about the event.
CCEV_D_CHAN_STATUS	The D channel status was changed as a result of the event on the D channel. Refer to the sample code in the cc_GetSAPI( ) and cc_GetCES( ) function descriptions for more information.
CCEV_DISCONNECTED	A DISCONNECT, RELEASE COMPLETE, or RELEASE message has been received by the application. This event may be received in any state except IDLE, DISCONNECTED, or NULL. The application must send a cc_DropCall( ) after this event is received. Use the cc_GetCallInfo( ) function to retrieve additional information about the event.
CCEV_DIVERTED	NAM with divert information has been received by the application. An outgoing call has been successfully diverted to another station.
CCEV_DROPACK	The network has honored a DROP request for a conference call; the request was made by sending the SndMsg_Drop message type via the cc_SndMsg( ) function. The event is sent on the corresponding line device. The CCEV_DROPACK event pertains only to a Custom BRI 5ESS switch type.
CCEV_DROPREJ	The network has not honored a DROP request for a conference call. The event is sent on the corresponding line device. The CCEV_DROPREJ event pertains only to a Custom BRI 5ESS switch type.
CCEV_ FACILITY	A FACILITY REQUEST message has been received by the application.
CCEV_FACILITYACK	A FACILITY_ACK message has been received by the application.
CCEV_FACILITYGLOBAL	An ISDN_FACILITY message containing a Global CRN value was received. This event is sent on the board level device, as the event is associated with all calls on the device. Upon receipt of this event, the application may issue a cc_GetNonCallMsg( ) function to retrieve the data into its local structure.
CCEV_FACILITYNULL	An ISDN_FACILITY message was received containing a Dummy (NULL) CRN. Upon receipt of this event, the application may issue a cc_GetNonCallMsg( ) function to retrieve the data into its local structure.
CCEV_FACILITYREJ	A FACILITY_REJ message has been received by the application.
CCEV_HOLDCALL	A HOLD message was received from remote equipment. The application may send cc_HoldAck( ) or cc_HoldRej( ) as a response.
CCEV_INFOGLOBAL	An ISDN_INFORMATION message containing a Global CRN value was received. This event is sent on the board level device, as the event is associated with all calls on the device. Upon receipt of this event, the application may issue a cc_GetNonCallMsg( ) function to retrieve the data into its local structure.
CCEV_INFONULL	An ISDN_INFORMATION message was received containing a NULL CRN. Upon receipt of this event, the application may issue a cc_GetNonCallMsg( ) function to retrieve the data into its local structure.
CCEV_L2FRAME	A data link layer frame has been received by the application. The application should use the cc_GetFrame( ) function to retrieve the received frame. It is the application's responsibility to analyze the contents of the frame.
CCEV_L2NOBFFR	There are no buffers available to save the incoming frame.
CCEV_NOFACILITYBUF	There are no buffers available to store the Network Facility Information Element (IE). This event can be ignored. The event is received for every incoming ISDN message that contains the Network Facility IE. The IE can be retrieved using the cc_GetInfoElem( ) function or the cc_GetCallInfo(U_IES) function.
CCEV_NOTIFY	A NOTIFY message has been received by the application. Use the cc_GetCallInfo( ) function to retrieve additional information about the event.
CCEV_NOTIFYGLOBAL	An ISDN_NOTIFY message containing a Global CRN value was received. This event is sent on the board level device, as the event is associated with all calls on the device. Upon receipt of this event, the application may issue a cc_GetNonCallMsg( ) function to retrieve the data into its local structure.
CCEV_NOTIFYNULL	An ISDN_NOTIFY message was received containing a Dummy (NULL) CRN. Upon receipt of this event, the application may issue a cc_GetNonCallMsg( ) function to retrieve the data into its local structure.
CCEV_NSI (DPNSS and Q.SIG only)	A Network Specific Indication (NSI) message was received from the network. The application should use cc_GetCallInfo( ) to retrieve the NSI string(s).
CCEV_ISDNMSG	An undefined ISDN message has been received by the application.
CCEV_PROCEEDING	An ISDN message has been received by the application. By default, the firmware will send this event to the application. The application may clear the CCMSK_PROCEEDING bit to block this event.
CCEV_PROGRESSING	A PROGRESS message has been received by the application. By default, the firmware will send this event to the application. The application may block this event by clearing the CCMSK_PROGRESS bit. Use the cc_GetCallInfo( ) function to retrieve additional information about the event.
CCEV_RCVTERMREG_ACK	The acceptance, by the switch, of a terminal initialization request from a station that has been configured as a North American User side (TE) station. This event occurs on a board level device, not a channel device. Use the USPID_BLK data structure to retrieve information about the event.
CCEV_RCVTERMREG_NACK	The rejection, by the switch, of a terminal initialization request from a station that has been configured as a North American User side (TE) station. This event occurs on a board level device, not a channel device. Use the TERM_NACK_BLK data structure to retrieve information about the event.
CCEV_REDIRECT	The firmware has reset its call state to Overlap Sending. The request to redirect was made by the switch to solicit more out-of-band digits. The CCEV_REDIRECT event pertains only to a Custom BRI 5ESS switch type configured as the TE (User side). A station configured as an NT (Network side) may generate a message, via the cc_SndMsg( ) function, causing this event.
CCEV_RETRIEVECALL	A RETRIEVE CALL acknowledge message was received from terminal equipment. The indicated terminal equipment requests reconnection of a call on hold. This event can only be received by an application when the application acts as a network.
CCEV_SERVICE	A SERVICE message has been received from the network.
CCEV_SERVICEACK	A SERVICE ACKNOWLEDGE message has been received from the network.
CCEV_SETCHANSTATE	The B channel status was changed as a result of cc_SetChanState( ) or a network request. This event occurs on a board level device, not a channel device.
CCEV_SETUP_ACK	A SETUP_ACK message has been received by the application.
CCEV_STATUS	A STATUS message has been received from the network.
CCEV_STATUS_ENQUIRY	A STATUS_ENQ message has been received from the network.
CCEV_TERM_REGISTER	An unsolicited event indicating that some action is required by the switch for the North American terminal initialization procedure. The application must respond to the event using the cc_TermRegisterResponse( ) function to either accept or reject the request to initialize the terminal. A Service Profile Identifier (SPID) value is associated with the event. A SPID is assigned by a phone company to a Fully Initializing Terminal (FIT) on an ISDN Basic Rate Interface (BRI) line. This event occurs on a board level device, not on a channel device. Use the SPID_BLK data structure to retrieve information about the event.
CCEV_TIMER	An unsolicited event indicating that a timer has expired.
CCEV_TRANSFERACK	A TRANSFER ACKNOWLEDGE MESSAGE was received from the network. The indicated network has accepted a request to transfer a call.
CCEV_TRANSFERREJ	A TRANSFER REJECT message was received from the network. The indicated network has rejected a request to transfer a call.
CCEV_TRANSIT (DPNSS and Q.SIG only)	After a transfer is established, transit messages are used for relating messages between the originating end and the terminating end.
CCEV_USRINFO	A USER INFORMATION message has been received by the application, indicating that a user-to-user information (UUI) event is coming. For example, this event is received in response to a cc_SndMsg( ) function call, from the far end, in which the msg_type is SndMsg_UsrInformation. Use the cc_GetCallInfo( ) function to retrieve the UUI.