Field	Description
calledaddr	The called number. Also referred to as the Direct Inward Dial (DID) number.
callingaddr	The calling number (if available). Also referred to as the Automatic Number Identification (ANI) number.

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Chapter 8

Feature Group D Protocol

8.1 Introduction

8.2 Capability Mask

8.3 Signaling Overview

8.4 Parameters

: 8.4.1 Editable Parameters
: 8.4.2 Non-editable Parameters

8.5 Special TCP Behavior

: 8.5.1 Inbound Calls: Receiving Digits

8.1 Introduction

This chapter describes the Feature Group D (FGD) signaling protocol and TCP parameters. It provides the following information: Overview of the signaling performed by the Feature Group D protocol. FGD TCP parameters. Operations that are specific to the FGD TCP within the framework of Natural Call Control.
The FGD TCP implements the specifications of the Feature Group D (FGD) switched access service. This service provides interconnection to the BOC (Bell Operating Companies) network for the provision of message telecommunications service/wide area telecommunications service (MTS/WATS) and MTS/WATS-type services. FGD service, which provides access to the trunk side of suitably equipped BOC switching systems, is available for termination and originating access.
If, in the past, you were using the FDI protocol, you should now migrate to the new Feature Group D (FGD) protocol.

8.2 Capability Mask

With the NCC service, an application can call nccQueryCapability to determine the capabilities of a protocol. nccQueryCapability returns a capabilitymask.
For information about the capabilities supported for NMS CAS protocols with NCC call control, refer to Appendix A.

8.3 Signaling Overview

Feature Group D signaling is derived from wink start signaling. Like wink start, FGD uses only two of the four bits per signaling direction supported by E1 Channel Associated Signaling (CAS) framing. The signaling channels supporting the FGD line signaling protocol are referred to as A_fand B_f in the forward direction, and A_b and B_b, in the backward direction. The forward channel indicates the condition of the outbound switch equipment and reflects the condition of the calling party's line. The backward channel indicates the condition of the called party's line (the inbound equipment).
The other bits in either direction (the C and D bits) usually have fixed values. However, their values may change from network to network.
The inbound side uses multiple winks to acknowledge reception of different series of incoming digits. The line signaling for a typical call is illustrated by the following table State Outbound A_fB_f Direction Inbound A_bB_b Idle 00 00 Seizure 11 00 Seizure Acknowledge 11 00-11-00 (wink) The outbound side starts to send the address informationusing MF tones. Feature Group D can transfer more than one digit field to speed up long distance calls. Every field starts with a KP tone (start of pulsing) and ends with an ST tone (end of pulsing). After each digits field the inbound side acknowledges the reception with a signaling bit wink. Register signaling first field: digit spill MF tones 00 Acknowledgment of first series of digit 00-11-00 (wink) Register signaling second field: digit spill MF tones 00 Once all the address information has been transferred, the inbound side must accept or reject the call (by sending the off-hook signaling code), or reject the call by playing busy. If the call is rejected, the outbound side should switch back to signaling AB = 00 (idle), clearing the line. Clear forward and idle 00 00 If the call is accepted, the inbound side answers the call by flipping both backward bits to 1. Answer - conversation state 11 11 Depending on which side hangs up the call first, a clear back signal or a clear forward signal is generated. Idle follows. Inbound hangs up first: Clear back 11 00 Outbound hangs up first: Clear forward 00 00 or 11 Idle 00 00 :

State	Outbound A_fB_f	Inbound A_bB_b
Idle	00	00
Seizure	11	00
Seizure Acknowledge	11	00-11-00 (wink)
The outbound side starts to send the address informationusing MF tones. Feature Group D can transfer more than one digit field to speed up long distance calls. Every field starts with a KP tone (start of pulsing) and ends with an ST tone (end of pulsing). After each digits field the inbound side acknowledges the reception with a signaling bit wink.
Register signaling first field: digit spill	MF tones	00
Acknowledgment of first series of digit		00-11-00 (wink)
Register signaling second field: digit spill	MF tones	00
Once all the address information has been transferred, the inbound side must accept or reject the call (by sending the off-hook signaling code), or reject the call by playing busy. If the call is rejected, the outbound side should switch back to signaling AB = 00 (idle), clearing the line.
Clear forward and idle	00	00
If the call is accepted, the inbound side answers the call by flipping both backward bits to 1.
Answer - conversation state	11	11
Depending on which side hangs up the call first, a clear back signal or a clear forward signal is generated. Idle follows.
Inbound hangs up first: Clear back	11	00
Outbound hangs up first: Clear forward	00	00 or 11
Idle	00	00

8.4 Parameters

The FGD TCP is programmed by the following parameters to implement the specifications of the supported countries and network operators. These parameters are stored within the parameter category NCC.X.ADI_FGD.
Parameters in this category fall into two groups: Parameters that program TCP/host interaction, or that act on features not regulated or that can change from switch to switch within the same network. You can freely edit these parameters to suit your implementation. Parameters that are signaling-specific: changing their values invalidates approvals for the board, and may cause the board to malfunction. These parameters are described here for reference purposes only. Note: If, in the past, you used the FDI protocol, you should now migrate to the new Feature Group D (FGD) protocol. For your convenience, the parameters that existed for FDI are compared to the new FGD parameters in the parameter table.

8.4.1 Editable Parameters

The following table describes NCC.X.ADI_FGD parameters (within the parameter category NCC.X.ADI_FGD) that you may modify. Also listed are the equivalent ADI.FGD parameters, to assist with migration from ADI to NCC. NCC Field Name ADI Field Name Unit Default Description optionflags optionflags mask 0x0 Not used sendanididwink signalingflags (bit 0) mask 0x0 If set, generate wink between ANI and DID digits. expectanididwink signalingflags (bit 1) mask 0x0 If set, expect wink between ANI and DID digits. expectfinalwink signalingflags (bit 2) mask 0x1 Determines if there is a final wink after digit reception: 0 There will be a final wink. 1 There will not be a wink.

NCC Field Name	ADI Field Name	Unit	Default	Description
optionflags	optionflags	mask	0x0	Not used
sendanididwink	signalingflags (bit 0)	mask	0x0	If set, generate wink between ANI and DID digits.
expectanididwink	signalingflags (bit 1)	mask	0x0	If set, expect wink between ANI and DID digits.
expectfinalwink	signalingflags (bit 2)	mask	0x1	Determines if there is a final wink after digit reception: `0` There will be a final wink. `1` There will not be a wink.

8.4.2 Non-editable Parameters

The following NCC.X.ADI_FGD parameters are country or network-specific, and cannot be modified. Also listed are the equivalent ADI.FGD parameters, to assist with migration from ADI to NCC.

Caution:

Most of the parameters that follow are signaling-specific: changing their value will invalidate any approval certificate for the used board, and may cause the board to malfunction. These parameters are described here for reference purposes only.

NCC Field Name

ADI Field Name

Unit

Default

Description

IDdigitmask

IDdigitmask

mask

0x28

This parameter determines which digits identify the ID field when they are received. Note that the first digit must be 1. The second digit is extracted from this parameter.
The mask is the following:
FEDC|BA98|7654|321-
1000|0000|0010|1000

setupbitqualtime

setupbitqualtime

ms

50

Bit signaling qualification time for on-hook to off-hook transitions.

permanentsignaltime

permanentsignaltime

ms

60000

Maximum time for remote end to remain off hook when trunk is not in the conversation state before a permanent signal condition is detected. Valid range is 1-65535.

defaultrejecttone

defaultrejecttone

integer

2

The default tone to play if the PC does not respond to an incoming call indication (see waitforPCtime):
0 Ringing
1 Busy
2 Reorder (fast busy)

winktime

winktime

ms

200

For incoming calls, the duration of the generated wink. Set this to 0 for no wink. Set to 0xFFFF for 350+440 Hz dial tone to be generated.

prewinktime

prewinktime

ms

100

Delay after incoming seizure is detected and before the start of the wink.

wait1stdigittime

wait1stdigittime

ms

7000

The maximum time to wait for the first incoming digit after the completion of the wink.

waitfordigittime

waitfordigitstime

ms

8000

The maximum time to wait for each incoming digit after the first one.

winkwaittime

winkwaittime

ms

10000

The maximum time to wait for the far end to wink for an outgoing call. Set this to 0 if no wink is expected.

maxwinktime

maxwinktime

ms

4900

The maximum duration of a detected wink.

predialtime

predialtime

ms

70

Delay to start of outgoing address signaling after end of wink is detected.

mfkpsttimeon

mfkpstontime

ms

80

Duration of tone on for MF, KP, and ST.

mfkpsttimeoff

mfkpstofftime

ms

80

Duration of tone off for MF, KP, and ST.

mfkpstampl

mfkpstampl

IDU

352

Amplitude of dialed tones.

releaseguardtime

releaseguardtime

ms

1000

Minimum on-hook internal between calls.

preanswertime

preanswertime

ms

100

Delay after the application has commanded to answer, and before the answered signal is sent to the network. The FGD TCP does not play a ring tone when accepting a call, but a certain delay is necessary.

noresourcemask

noresourcemode

integer

0

Mask that controls behavior when no resource is granted on inbound calls.
0 No signaling; just send error
1 Generate wink, then send error

customSTtones1

customSTtones
(lowest 5 bits)

mask

0x0

Use to send customized ST tones.

customSTtone2

customSTtones
(middle 5 bits)

mask

0x0

Use to send customized ST tones.

customSTtone3

customSTtones
(highest 5 bits)

mask

0x0

Use to send customized ST tones.

alarmsonqualtime

alarmsqualtime (low byte)

ms

5000

Determines the qualification time for trunk alarms (time to wait after the commencement of a trunk alarm before the TCP is notified).

alarmsoffqualtime

alarmsqualtime (high byte)

ms

4000

Determines the qualification time for trunk alarm end (time to wait after a trunk alarm state ended before the TCP is notified).
The following parameters are reserved for NMS internal use: alarmsonqualtime alarmsoffqualtime

*Caution:*	Most of the parameters that follow are signaling-specific: changing their value will invalidate any approval certificate for the used board, and may cause the board to malfunction. These parameters are described here for reference purposes only.

NCC Field Name	ADI Field Name	Unit	Default	Description
IDdigitmask	IDdigitmask	mask	0x28	This parameter determines which digits identify the ID field when they are received. Note that the first digit must be 1. The second digit is extracted from this parameter. The mask is the following: `FEDC\|BA98\|7654\|321-` `1000\|0000\|0010\|1000`
setupbitqualtime	setupbitqualtime	ms	50	Bit signaling qualification time for on-hook to off-hook transitions.
permanentsignaltime	permanentsignaltime	ms	60000	Maximum time for remote end to remain off hook when trunk is not in the conversation state before a permanent signal condition is detected. Valid range is 1-65535.
defaultrejecttone	defaultrejecttone	integer	2	The default tone to play if the PC does not respond to an incoming call indication (see waitforPCtime): `0` Ringing `1` Busy `2` Reorder (fast busy)
winktime	winktime	ms	200	For incoming calls, the duration of the generated wink. Set this to 0 for no wink. Set to `0xFFFF` for 350+440 Hz dial tone to be generated.
prewinktime	prewinktime	ms	100	Delay after incoming seizure is detected and before the start of the wink.
wait1stdigittime	wait1stdigittime	ms	7000	The maximum time to wait for the first incoming digit after the completion of the wink.
waitfordigittime	waitfordigitstime	ms	8000	The maximum time to wait for each incoming digit after the first one.
winkwaittime	winkwaittime	ms	10000	The maximum time to wait for the far end to wink for an outgoing call. Set this to 0 if no wink is expected.
maxwinktime	maxwinktime	ms	4900	The maximum duration of a detected wink.
predialtime	predialtime	ms	70	Delay to start of outgoing address signaling after end of wink is detected.
mfkpsttimeon	mfkpstontime	ms	80	Duration of tone on for MF, KP, and ST.
mfkpsttimeoff	mfkpstofftime	ms	80	Duration of tone off for MF, KP, and ST.
mfkpstampl	mfkpstampl	IDU	352	Amplitude of dialed tones.
releaseguardtime	releaseguardtime	ms	1000	Minimum on-hook internal between calls.
preanswertime	preanswertime	ms	100	Delay after the application has commanded to answer, and before the answered signal is sent to the network. The FGD TCP does not play a ring tone when accepting a call, but a certain delay is necessary.
noresourcemask	noresourcemode	integer	0	Mask that controls behavior when no resource is granted on inbound calls. `0` No signaling; just send error `1` Generate wink, then send error
customSTtones1	customSTtones (lowest 5 bits)	mask	0x0	Use to send customized ST tones.
customSTtone2	customSTtones (middle 5 bits)	mask	0x0	Use to send customized ST tones.
customSTtone3	customSTtones (highest 5 bits)	mask	0x0	Use to send customized ST tones.
alarmsonqualtime	alarmsqualtime (low byte)	ms	5000	Determines the qualification time for trunk alarms (time to wait after the commencement of a trunk alarm before the TCP is notified).
alarmsoffqualtime	alarmsqualtime (high byte)	ms	4000	Determines the qualification time for trunk alarm end (time to wait after a trunk alarm state ended before the TCP is notified).

8.5 Special TCP Behavior

The following sections describe operations that are specific to the FGD TCP within the framework of Natural Call Control.

8.5.1 Inbound Calls: Receiving Digits

For FGD, after NCCEVN_INCOMING_CALL is received, the following fields of the NCC_CALL_STATUS structure contain information relevant to the call: Field Description calledaddr The called number. Also referred to as the Direct Inward Dial (DID) number. callingaddr The calling number (if available). Also referred to as the Automatic Number Identification (ANI) number.

The following field is in the NCC_CAS_EXT_CALL_STATUS structure: Field Description carrierid Carrier ID information (if available).
With FGD, all digits are MFs; no DTMF signaling is used. By default, a group of incoming digits begins with a KP tone, followed by digits, then an ST tone. This may be followed by a wink, then perhaps one or more other KP-digits-ST-wink sequences.
When the TCP receives inbound digits, it checks the digits in each sequence to determine what type of information it contains, as described in the following table: If... And... Then the TCP assumes that... The first digit in the sequence is a 1 The next digit is a 0 The call is a test call. All digits go in the calledaddr field. The first digit in the sequence is a 1 The following digits in the sequence match the digits specified with the internal parameter The sequence contains carrier ID information. Digits are placed in the originalcalledaddr field. The first digits in the sequence are "95" The call is a test call. All digits go in the calledaddr field. The digits in the sequence do not match any of the above scenarios No previous digit sequences have been received The sequence contains ANI digits. They are placed in the callingaddr field. The digits in the sequence do not match any of the above scenarios ANI information has been received The sequence contains DID digits. They are placed in the calledaddr field.

The following parameters affect the way the FGD TCP accepts, processes and presents the incoming digits to the host: Field Description sendanididwink If set, generate wink between ANI and DID digits. expectanididwink If set, expect wink between ANI and DID digits. sendfinalwink If zero, then there will be a final wink after digit reception. If set, there will not be a wink. IDdigitmask This parameter determines which digits identify the ID field when they are received. Note that the first digit must be 1. The second digit is extracted from this parameter. The mask is the following: FEDC|BA98|7654|321- 1000|0000|0010|1000

Field	Description
carrierid	Carrier ID information (if available).

If...	And...	Then the TCP assumes that...
The first digit in the sequence is a 1	The next digit is a 0	The call is a test call. All digits go in the calledaddr field.
The first digit in the sequence is a 1	The following digits in the sequence match the digits specified with the internal parameter	The sequence contains carrier ID information. Digits are placed in the originalcalledaddr field.
The first digits in the sequence are "95"		The call is a test call. All digits go in the calledaddr field.
The digits in the sequence do not match any of the above scenarios	No previous digit sequences have been received	The sequence contains ANI digits. They are placed in the callingaddr field.
The digits in the sequence do not match any of the above scenarios	ANI information has been received	The sequence contains DID digits. They are placed in the calledaddr field.

Field	Description
sendanididwink	`If set, generate wink between ANI and DID digits.`
expectanididwink	`If set, expect wink between ANI and DID digits.`
sendfinalwink	If zero, then there will be a final wink after digit reception. If set, there will not be a wink.
IDdigitmask	This parameter determines which digits identify the ID field when they are received. Note that the first digit must be 1. The second digit is extracted from this parameter. The mask is the following: `FEDC\|BA98\|7654\|321-` `1000\|0000\|0010\|1000`

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