# ISDN_PROTOCOL_PARMS_Q931CC parameters

The ISDN_PROTOCOL_PARMS_Q931CC structure contains parameters that configure the ISDN protocol stack for Q.931 call control through the ACU. Either this structure or ISDN_PROTOCOL_PARMS_LAPD is passed to isdnStartProtocol, depending on how the ISDN protocol stack is configured.

For more information, refer to Initializing ISDN protocol stack instances. For a definition of the data structure, see ISDN_PROTOCOL_PARMS_Q931CC structure.

Type | Parameter | Description | Default value | Range of values
--- | --- | --- | --- | ---
DWORD | size | Size of the structure. | None. |
WORD | rate | Data rate. | ISDN_RATE_64K | ISDN_RATE_64K, ISDN_RATE_56K
WORD | t309 | T309 in use flag indicates if data link release and establish timers are in effect (used by D channel backup protocol). See D channel backup. | 0 | 0, 1
timer_val_t | xxx | Timer values by country or operator. | See Timer overview. | See Timer overview.
BYTE | services_list[ ] | Services supported on incoming calls. | All services. See services_list field. | All services.
WORD | max_FEC_errors | Maximum number of framing errors allowed during the T198 interval. | 20 | 0 or more ms
timer_val_t | t101 | Milliseconds of bad framing before disabling sending of D channel packets. | 750 | 0 or more ms
timer_val_t | t102 | Milliseconds of good framing before enabling sending of D channel packets. | 50 | 0 or more ms
timer_val_t | t198 | Observation period for frame error count. | 5 | 0 or more seconds
WORD | tei_time_assignment | TEI time assignment. | 0 | (reserved)
WORD | tei_time_removal | TEI time removal. | 0 | (reserved)
BYTE | tei[3] | TEI values. | 0 | (reserved)
BYTE | digitstoroute | Number of digits needed to route when using overlap receiving. | 0 | 0 or more
WORD | in_calls_behaviour | Incoming calls behavior. | 0 | See in_calls_behaviour field.
WORD | out_calls_behaviour | Outgoing calls behavior. | 0 | See out_calls_behaviour field.
WORD | ns_behaviour | Bits controlling NS automatic responses. | 0 | See ns_behaviour field.
WORD | acu_behaviour | Bits controlling ACU automatic responses. | 0 | See acu_behaviour field.
BYTE | qsig_source_party_nb_type | Type of PINX node address. Used for network node addressing in supplementary services. | None. | See qsig_source_party_nb_type field.
BYTE | qsig_source_type_of_nb | Type of public PINX number. Used for network node addressing in supplementary services. | None. | See qsig_source_type_of_nb field.
BYTE | qsig_source_addr | Node address. | None. | None.
BYTE | aoc_s_presubscribed | Availability of Advice-of-Charge (Start of Call) supplementary service. | OFF | ON, OFF
BYTE | aoc_d_presubscribed | Availability of Advice-of-Charge (Start of Call) supplementary service. | OFF | ON, OFF
BYTE | aoc_e_resubscribed | Availability of Advice-of-Charge (Start of Call) supplementary service. | OFF | ON, OFF
BYTE | bpad2[1] | Padding for 8 byte alignment. | 0 | 0
WORD | nfas_group | NFAS group number if duplicate NAI values. | 0 | 0 - 255
BYTE | bpad3[2] | Padding for 8 byte alignment. | 0 | 0
WORD | rfu1 | Reserved for future use. | 0 | 0
WORD | rfu2 | Reserved for future use. | 0 | 0

For details on the BYTE field, see the NMS ISDN Supplementary Services Developer's Reference Manual.

## Protocol parameter settings

The following code segment illustrates the typical settings of the protocol parameter to isdnStartProtocol for application access to ACU SAP.

memset(&cc_parms, 0, sizeof(ISDN_PROTOCOL_PARMS_Q931CC));
cc_parms.rate = ISDN_RATE_64K;
cc_parms.services_list[0] = VOICE_SERVICE;
cc_parms.services_list[1] = NO_SERVICE;