AG ISDN Messaging API Developer's Reference Manual P/N 6272-12

Introduction
ISDN_PROTOCOL_PARMS_Q931CC
ISDN_PROTOCOL_PARMS_LAPD
CONFIG_DL_SAPI

Appendix C: Parameters

Introduction

This section lists the default settings of the parameters passed to isdnStartProtocol by means of the parms argument.

ISDN_PROTOCOL_PARMS_Q931CC

The ISDN_PROTOCOL_PARMS_Q931CC structure contains parameters which configure the ISDN protocol stack for Q.931 call control via the ACU. Either this structure or ISDN_PROTOCOL_PARMS_LAPD are passed to isdnStartProtocol, depending upon how the ISDN protocol stack is to be configured. For details, see Section 4.4.1. For a definition of the data structure, see Section 6.3.1.

Type

Parameter

Description

Default Value

Range of Values

WORD

hdlc_channel

HDLC channel index.

0

0

WORD

rate

Data rate.

ISDN_RATE_64K

ISDN_RATE_64K, ISDN_RATE_56K

CONFIG_DL_SAPI

sapi_sig

Data link signaling layer configuration.

(See below)

CONFIG_DL_SAPI

sapi_x25

DL_SAPI_X25.

0

Not supported.

CONFIG_DL_SAPI

sapi_mdl

Data link management component configuration.

(See below)

CONFIG_DL_SAPI

other[2]

User defined SAPIs.

0

Not supported.

timer_val_t

xxx

Timer values by country/operator.

(See Appendix D)

(See Appendix D)

WORD

t309

T309 in use flag indicates if data link release and establish timers are in effect.

non-zero

0, non-zero

BYTE

services_list[ ]

Services supported on incoming calls.

All services (See below)

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

ms. of bad framing before disabling sending D channel packets.

750

0 or more ms.

timer_val_t

t102

ms. of good framing before enabling sending D channel packets.

50

0 or more ms.

timer_val_t

t198

Integration period for framing errors.

5

0 or more sec.

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_behavior

Incoming calls behavior.

0

(See below)

WORD

out_calls_behavior

Outgoing calls behavior.

0

(See below)

The following code segment illustrates the typical settings of the protocol parameter to isdnStartProtocol for application access to ACU SAP. The two SAPIs required to be initialized below the ACU are sapi_sig (network signaling) and sapi_mdl (data link management). Notice that these data structures need only be initialized to 0 and the enabled bit set so that the default fields will be initialized by the ACU layer on the board.

The partner field indicates the point to which the equipment is being connected, i.e. the "partner" equipment for a system being configured as terminal equipment is the Network Terminating device (NT).

memset(&cc_parms, 0, sizeof(ISDN_PROTOCOL_PARMS_Q931CC));    
cc_parms.rate = ISDN_RATE_64K;    
cc_parms.sapi_sig.enabled = TRUE;    
cc_parms.sapi_mdl.enabled = TRUE;    
cc_parms.services_list[0] = ACU_VOICE_SERVICE;    
cc_parms.services_list[1] = ACU_NO_SERVICE;

services_list Sub-Structure

The services_list data structure included in ISDN_PROTOCOL_PARMS_ Q931CC consists of a set of up to CC_MX_SERVICES elements, which together define the set of ACU services required by an instance of the ISDN protocol stack.

By default, all services are accepted. If you specify certain services only, if an incoming call requests a different service, the protocol stack automatically rejects the call.

The following available services are defined in isdnacu.h:

Service	Description
ACU_VOICE_SERVICE	Voice (telephony)
ACU_AUDIO_7_SERVICE	7 kHz audio
ACU_DATA_SERVICE	Unrestricted data
ACU_DATA_56KBS_SERVICE	Data at 56 kbit/s
ACU_DATA_TRANS_SERVICE	Transparent data
ACU_X25_SERVICE	X.25 in Circuit Mode
ACU_X25_PACKET_SERVICE	X.25 in Packet mode
ACU_MODEM_SERVICE	Modem data
ACU_FAX_SERVICE	Fax G3
ACU_FAX_4_SERVICE	Fax G4
ACU_V110_SERVICE	V110 rate adaption
ACU_V120_SERVICE	V120 rate adaption
ACU_VIDEO_SERVICE	Video
ACU_VOICE_RELAY_SERVICE	Voice (telephony) when using physical relay entity
ACU_DATA_RELAY_SERVICE	Unrestricted data when using physical relay entity
ACU_DATA_56KBS_RELAY_SERVICE	Data at 56 kbit/s when using physical relay entity
ACU_DATA_TRANS_RELAY_SERVICE	Transparent data when using physical relay entity
ACU_X25_RELAY_SERVICE	X.25 in Circuit Mode when using physical relay entity
ACU_MODEM_RELAY_SERVICE	Modem data when using physical relay entity
ACU_FAX_RELAY_SERVICE	Fax G3 when using physical relay entity

The services array must be terminated by ACU_NO_SERVICE. Thus you can specify at most CC_MX_SERVICES minus 1.

Note: The delivery of some of these services may be regulated by local authorities. You may be responsible for formally certifying these services in some countries. Check with the local authority for more specific information on these limitations.

in_calls_behavior Sub-Structure

The Parameters in the in_calls_behavior sub-structure included in ISDN_ PROTOCOL_PARMS_Q931CC determine how an incoming call is handled by the ISDN protocol stack. Refer to isdnparm.h for more details.

These configuration fields are bit fields. Each determines a particular element of the ISDN protocol stack's behavior. The values are defined as follows:

Bit	Description
CC_SEND_ALERT_IN	Determines if ACU_ALERT_IN is sent automatically after ACU_CONN_IN. If this bit is set, the ACU generates an ACU_ALERT_IN after having sent an ACU_CONN_IN.
CC_SEND_CALL_PROC_RQ	Determines if NS_CALL_PROC_RQ is automatically sent on incoming calls. If this bit is set, the ACU sends an NS_CALL_PROC_RQ on an incoming call. Otherwise, the application must send ACU_CALL_PROC_RQ for this. (Note that this message is optional).
CC_VOICE_ALERT_RQ	Determines if NS_ALERT_RQ is automatically sent when a TELEPHONY call arrives. If this bit is set, the ACU sends an NS_ALERT_RQ on a TELEPHONY incoming call.
CC_DATA_ALERT_RQ	Determines if NS_ALERT_RQ is automatically sent when a NOT TELEPHONY call arrives. If this bit is set, the ACU sends an NS_ALERT_RQ on a NOT TELEPHONY incoming call.
CC_VOICE_CONN_RS	Determines if TELEPHONY incoming calls are automatically answered or not. If this bit is set, the ACU sends an NS_CONN_RS to NS on TELEPHONY incoming calls.
CC_DATA_CONN_RS	Determines if NOT TELEPHONY incoming calls are automatically answered or not. If this bit is set, the ACU sends an NS_CONN_RS to NS on NOT TELEPHONY incoming calls.
CC_TRANSPARENT_OVERLAP_RCV	Transparent processing of overlap receiving mode. If this bit is set, the ACU sends an ACU_CONN_IN to the application even if all digits have not yet arrived (i.e. the 'Sending Complete' IE is not present). Additional incoming digits are sent in ACU_DIGIT_IN messages. If this bit is not set, the ACU waits for at least CC_NB_DIGIT_TO_ROUTE digits to come in before sending an ACU_CONN_IN message to the application. Any additional digits coming via NS_INFO_IN messages are ignored.
CC_BEHAVIOR_NIL	If this bit is set to 1 and all other bits in in_calls_behavior are set to 0, no messages are automatically sent by the ACU in response to an incoming call. The application must build and send all messages. If any of the other bits are set, this bit is ignored. The ACU will send all messages you specify.

If in_calls_behavior is set to 0 or not set at all, the ISDN protocol stack behaves as follows:

NT side: CC_SEND_CALL_PROC_RQ set, all others cleared.

TE side: CC_VOICE_ALERT_RQ and CC_DATA_ALERT_RQ set, all others cleared.

out_calls_behavior Sub-Structure

The parameters in the out_calls_behavior sub-structure included in ISDN_PROTOCOL_PARMS_Q931CC determine how an outgoing call is handled by the ISDN protocol stack. Refer to isdnparm.h for more details.

These configuration fields are bit fields. The values are defined as follows:

Bit	Usage
CC_USER_SENDING_COMPLETE	Determines if 'Sending-complete' information element is automatically generated in ACU_CONN_RQ. If this bit is set, the ACU does not automatically generate the 'Sending-complete' information element. Instead, the application must request it in ACU_CONN_RQ. If the bit is not set, the ACU will generate the 'Sending-complete' information element automatically in the ACU_CONN_RQ only. This bit does not affect ACU_DIGIT_RQ (the application must specify the acu_digit_rq_ sending_complete field value explicitly).
CC_SEND_CONN_CO_ON_PROGRESS	If this bit is set, the ACU sends ACU_CONN_CO when it receives NS_PROGRESS_IN for a VOICE call. Otherwise, it waits for NS_CONN_CO to send ACU_CONN_CO.
CC_BEHAVIOR_NIL	If this bit is set to 1 and all other bits in out_calls_behavior are set to 0, no messages are automatically sent by the ACU during an outgoing call. The application must build and send all messages. If any of the other bits are set, this bit is ignored. The ACU will send all messages you specify.

If out_calls_behavior is set to 0 or not set at all, the ISDN protocol stack behaves as if all out_calls_behavior bits are cleared.

ISDN_PROTOCOL_PARMS_LAPD

The ISDN_PROTOCOL_PARMS_LAPD structure contains parameters which configure the ISDN protocol stack for LAPD. Either this structure or ISDN_PROTOCOL_PARMS_Q931CC are passed to isdnStartProtocol, depending upon how the ISDN protocol stack is to be configured. For details, see Section 4.4.1. For a definition of the data structure, see Section 6.3.2.

CONFIG_DL_SAPI

The following parameter structure is included in the configuration structure ISDN_PROTOCOL_PARMS_Q931CC and ISDN_PROTOCOL_PARMS_ LAPD. Two of the four configuration structures specified in each of these structures must be enabled. The following tables enumerate the default settings of the sapi_sig and the sapi_mdl, describing the parameters for the signaling layer and the data link management layer, respectively.

CONFIG_DL_SAPI sapi_sig Defaults

Type

Parameter

Description

Default

Range of Values

WORD

enabled

SAPI enabled.

1

0, non-zero

WORD

override_defaults

Override default SAPI configuration.

0

0, non-zero

BYTE

BYTE sapi

SAPI identifier.

0

0

BYTE

modulo

LAP frame sequencing in N(R) and N(S) fields of I-frames

128

8, 128

BYTE

k

Window size.

N/A

N/A

BYTE

n_cep

Number of connection endpoints.

2

0-255

timer_val_t

t200

Time to wait for an acknowledgement to a frame before initiating recovery (DL).

1

0 or more sec.

timer_val_t

t201

Minimum time between TEI identity check messages (MDL).

1

0 or more sec.

timer_val_t

t202

Minimum time between TEI identity request (MDL).

2

0 or more sec.

timer_val_t

t203

Maximum time with no frames exchanged (DL watchdog timer).

10

30 (for AT&T only)

0 or more sec.

BYTE

n200

Maximum number of re-transmissions of a frame (SAPI_SIG).

3

0 or more

BYTE

n202

Maximum number of re-transmissions of TEI identity message (SAPI_MDL).

3

0 or more

WORD

n201

I frame maximum size

260

1-260

BYTE

xid_max_val

XID retransmission max value: X.32 identification.

0

Not supported.

BYTE

lapf_add_format

LAP F address format.

0

Not supported.

BYTE

lapf_discard

LAP F discard eligibility.

0

Not supported.

BYTE

lapf_dc

DLCI or DL-CORE.

0

Not supported.

timer_val_t

xid_timer

XID retransmission timer value.

0

Not supported.

timer_val_t

reserved

N/A

0

(reserved)

CONFIG_DL_SAPI sapi_mdl Defaults

Type

Parameter

Description

Default

Range of Values

WORD

enabled

SAPI enabled.

1

0, non-zero

WORD

override_defaults

Override default SAPI configuration.

0

0, non-zero

BYTE

BYTE sapi

SAPI identifier.

63

63

BYTE

modulo

LAP frame sequencing in N(R) and N(S) fields of I-frames.

128

8, 128

BYTE

k

Window size.

N/A

N/A

BYTE

n_cep

Number of connection endpoints.

2

0-255

timer_val_t

t200

Time to wait for an acknowledgement to a frame before initiating recovery (DL).

1

0 or more sec.

timer_val_t

t201

Minimum time between TEI identity check messages (MDL).

1

0 or more sec.

timer_val_t

t202

Minimum time between TEI identity request (MDL).

2

0 or more sec.

timer_val_t

t203

Maximum time with no frames exchanged (DL watchdog timer).

10

30 (for AT&T only)

0 or more sec.

BYTE

n200

Maximum number of re-transmissions of a frame (SAPI_SIG).

3

0 or more

BYTE

n202

Maximum number of re-transmissions of TEI identity message (SAPI_MDL).

3

0 or more

WORD

n201

I frame maximum size

260

1-260

BYTE

xid_max_val

XID retransmission maximum value: X.32 identification.

0

Not supported.

BYTE

lapf_add_format

LAP F address format.

0

Not supported.

BYTE

lapf_discard

LAP F discard eligibility.

0

Not supported.

BYTE

lapf_dc

DLCI or DL-CORE.

0

Not supported.

timer_val_t

xid_timer

XID retransmission timer value.

0

Not supported.

timer_val_t

reserved

N/A

0

(reserved)

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Type	Parameter	Description	Default Value	Range of Values
WORD	hdlc_channel	HDLC channel index.	0	0
WORD	rate	Data rate.	ISDN_RATE_64K	ISDN_RATE_64K, ISDN_RATE_56K
CONFIG_DL_SAPI	sapi_sig	Data link signaling layer configuration.	(See below)
CONFIG_DL_SAPI	sapi_x25	DL_SAPI_X25.	0	Not supported.
CONFIG_DL_SAPI	sapi_mdl	Data link management component configuration.	(See below)
CONFIG_DL_SAPI	other[2]	User defined SAPIs.	0	Not supported.
timer_val_t	xxx	Timer values by country/operator.	(See Appendix D)	(See Appendix D)
WORD	t309	T309 in use flag indicates if data link release and establish timers are in effect.	non-zero	0, non-zero
BYTE	services_list[ ]	Services supported on incoming calls.	All services (See below)	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	ms. of bad framing before disabling sending D channel packets.	750	0 or more ms.
timer_val_t	t102	ms. of good framing before enabling sending D channel packets.	50	0 or more ms.
timer_val_t	t198	Integration period for framing errors.	5	0 or more sec.
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_behavior	Incoming calls behavior.	0	(See below)
WORD	out_calls_behavior	Outgoing calls behavior.	0	(See below)