(Page 1 of 1 in this chapter)


Chapter 10

US Wink Start Protocols


10.1 Introduction
10.2 Signaling Overview
10.2.1 One- and Two-way Digital and Analog Wink Start
10.2.2 Feature Group D Inbound (FDI0)
10.3 Parameters
10.3.1 WNK parameters (two-way wink start)
10.3.2 DID Parameters (Inbound Wink Start)
10.3.3 OGT Parameters (outbound wink start)
10.3.4 FDI Parameters (Inbound Feature Group D)
10.4 Special TCP Behavior
10.4.1 Inbound Calls: Retrieving Digits All at Once
10.4.2 Inbound Calls: Retrieving Digits One at a Time
10.4.3 Outbound Calls: Digit Format

10.1 Introduction

This chapter provides the following information:

· Overview of the signaling performed by the protocols covered in the United States Wink Start (WNK) family of TCPs

· Parameters used by the various TCPs in the family

· Operations specific to these TCPs within the framework of Natural Call Control.

The United States Wink Start TCP family comprises protocols derived from the Wink Start T1 protocol. This is a common protocol used by PSTNs to communicate with PBXs, and also to communicate internally. The protocol owes its name to the "wink" (brief variation of signaling bits) that the inbound side sends to the outbound side to acknowledge a line seizure.

Natural MicroSystems provides the following types of Wink Start-derived TCPs:
Trunk Control Protocol

Description

wnk0.tcp

Two-way wink start over T1 trunks and analog DID lines

did0.tcp

Inbound wink start over T1 trunks and analog DID lines

ogt0.tcp

Outbound wink start over T1 trunks and analog DID lines

fdi0.tcp

Inbound Feature Group D over T1

wnk1.tcp

Two-way wink start over analog (E&M) line

did1.tcp

Inbound wink start over analog (E&M) line

ogt1.tcp

Outbound wink start over analog (E&M) line

10.2 Signaling Overview

10.2.1 One- and Two-way Digital and Analog Wink Start

This section describes the protocols implemented by the WNK0 and 1, DID0 and DID 1, and OGT0 and 1 TCPs.

The protocol is symmetrical (same implementation form the network or from a customer premises equipment).

The line signaling for a typical call is illustrated by the following table:
State

Outbound AfBf

Direction

Inbound AbBb

Idle

00

\xdf

00

Seizure

11

00

Seizure Acknowledge

11

\xdf

00-11-00 (wink)

Here the outbound side starts to send the address information. This can be done by means of DTMF tones, MF tones, or decadic pulses. If the method is decadic pulses, the Af bit is switched off (pulse on) and on (pulse off) repeatedly to signal the digits.

Register signaling: digit spill

DTMF or MF

00

Register signaling: pulse dial

00 pulse on

00

11 pulse off

00

All the address information has been transferred, now the inbound side must accept or reject the call. It does so by playing the ring or the busy tone on the voice path.

If the call is rejected, the outbound side is supposed to switch back to signaling AB = 00 (idle) thus 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

\xdf

11

Depending on which of the sides hangs up the call first, we have a clear back signal, or a clear forward signal. Idle follows.

Inbound hangs up first: Clear back

11

\xdf

00

Outbound hangs up first: Clear forward

00

00 or 11

Idle

00

\xdf

00

In analog variations the digital bit signaling is translated into E & M or DID analog signaling by the line interface circuitry on the board.

The wink start protocol can transfer ANI (caller ID) information in addition to DID digits (direct inward dialing - the called address). A separator tone is used to distinguish between DID and ANI digits in the DTMF digit spill. Usually the separator tone is a `*'(941+1209 Hz). The parameter ADI.WNK.dtmfmask (see following table) programs the TCP behavior with respect to ANI digits.

10.2.2 Feature Group D Inbound (FDI0)

Feature Group D is a protocol derived from wink start signaling. In fact, 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 AfBf

Direction

Inbound AbBb

Idle

00

\xdf

00

Seizure

11

00

Seizure Acknowledge

11

\xdf

00-11-00 (wink)

Here the outbound side starts to send the address information. This is done by means of MF tones. Feature Group D can transfer more than one digit field. This is done to speed up long distance calls. Every field starts with a `KP' tone (start of pulsing) and ends with a `ST' tone (end of pulsing). After each digits field the inbound side acknowledges the reception with a signaling bits wink.

Register signaling first field: digit spill

MF tones

00

Acknowledgment of first series of digit

\xdf

00-11-00 (wink)

Register signaling second field: digit spill

MF tones

00

All the address information has been transferred, now the inbound side must accept or reject the call. FDI rejects the call by playing busy. If the call is accepted instead the off-hook signaling code is sent.

If the call is rejected, the outbound side is supposed to switch back to signaling AB = 00 (idle) thus 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

\xdf

11

Depending on which of the sides hangs up the call first, we have a clear back signal, or a clear forward signal. Idle follows.

Inbound hangs up first: Clear back

11

\xdf

00

Outbound hangs up first: Clear forward

00

00 or 11

Idle

00

\xdf

00

10.3 Parameters

The following sections describe United States Wink Start TCP parameters.

10.3.1 WNK parameters (two-way wink start)

Field Name

Type/Unit

Default

Description

Changeable?

qualaddron

ms

50

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

no

qualaddroff

ms

50

Bit signaling qualification time for off-hook to on-hook transitions during call set-up.

no

qualdisconnect

ms

150

Bit signaling qualification time for off-hook to on-hook transitions after address signaling is completed.

no

qualpermsignal

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.

no

reserved

ms

0

Reserved.

no

mfflags

mask

3

Mask that controls behavior when using MF signaling. Set adistart.dial.method =2 so that adiPlaceCall uses MF digits. A value may be formed by ORing any of the following:
Value Definition
1 Begin with KP tone
2 End with ST tone

yes

numdigits

count

3

The expected number of digits for incoming calls. If an incoming call is detected with fewer digits than what is specified in this parameter, ADIEVN_INCOMING_CALL is sent up to the host after the wait-for-digits timer (adi.wnk.waitfordigitstime) has expired. At least one digit must be detected for this to occur.

It is up to the application to parse the digit string and to decide whether or not to accept the call. Calls with a number of digits equal to or greater than the number in adi.wnk.numdigits behave normally.

yes

defaulttone

integer

2

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

yes

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.

no

detectmode

integer

0

Type of incoming address signaling:
Value Definition
0 DTMF and dial pulse
2 MF

yes

waitforPCtime

ms

10000

The maximum time to wait for the PC to respond to an incoming call indication before playing a default tone (see defaulttone).

yes

prewinktime

ms

100

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

yes

ringontime

ms

1000

The length of each generated ring tone.

yes

ringofftime

ms

3000

The length of the silent interval between generated ring tones.

yes

busyontime

ms

500

The length of each generated busy tone.

yes

busyofftime

ms

500

The length of the silent interval between generated busy tones.

yes

reorderontime

ms

250

The length of each generated reorder (fast busy) tone.

yes

reorderofftime

ms

250

The length of the silent interval between generated reorder tones.

yes

wait1stdigittime

ms

7000

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

yes

waitfordigitstime

ms

8000

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

If an incoming call is detected with fewer digits than what is specified in the adi.wnk.numdigits parameter, ADIEVN_INCOMING_CALL is sent up to the host after this wait-for-digits timer has expired. At least one digit must be detected for this to occur.

yes

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.

yes

minwinktime

ms

100

The minimum duration of a detected wink.

no

maxwinktime

ms

4900

The maximum duration of a detected wink.

no

predialtime

ms

70

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

no

mfkpstontime

ms

80

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

no

mfkpstofftime

ms

80

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

no

mfkpstampl

internal

352

Amplitude of dialed tones.

no

releaseguardtime

ms

1000

Minimum on-hook internal between calls.

yes

dtmfmask

mask

1000

A few flags to manage the reception of ANI digits.

· Bit 0 (&0x1). If set to 1, DTMF `#' symbolizes end of digit string

· Bit 1 (&0x2). If set to 1, DTMF `*' appears between the ANI and DID digits in the received digit stream.

· Bit 2 (&0x4). If set, the ANI field comes before the '*' (the default is DID before ANI).

If expecting ANI digits, change the value of the numbdigits parameter accordingly.

yes

maxresourcetime

ms

10000

Maximum time to wait for a call setup resource to be available (AG Quad T with resource management only)

yes

noresourcemode

integer

0

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

yes

xfersupport

mask

1

Flag to select whether PBX transfer is allowed.

Value Definition
0 Transfer commands are
disabled
1 Transfer commands are
allowed

yes

xferstring

String[6]

"!;"

Prefix of feature code for transfer operation. The default string "!;" generates a flash hook, then waits for a dialtone.

yes

connstring

String[6]

"!"

Prefix of feature code for reconnect from transfer operation. The default string "!" generates a flash hook.

yes

10.3.2 DID Parameters (Inbound Wink Start)
Field Name

Type/Unit

Default

Description

Changeable?

qualaddron

ms

50

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

no

qualaddroff

ms

50

Bit signaling qualification time for off-hook to on-hook transitions during call set-up.

no

qualdisconnect

ms

150

Bit signaling qualification time for off-hook to on-hook transitions after address signaling is completed.

no

qualpermsignal

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.

no

reserved

ms

0

Reserved.

no

mfflags

mask

3

Mask that controls behavior when using MF signaling. Set adistart.dial.method =2 so that adiPlaceCall uses MF digits. A value may be formed by ORing any of the following:
Value Definition
1 Begin with KP tone
2 End with ST tone

yes

numdigits

count

3

The expected number of digits for incoming calls. If an incoming call is detected with fewer digits than what is specified in this parameter, ADIEVN_INCOMING_CALL is sent up to the host after the wait-for-digits timer (adi.wnk.waitfordigitstime) has expired. At least one digit must be detected for this to occur.

It is up to the application to parse the digit string and to decide whether or not to accept the call. Calls with a number of digits equal to or greater than the number in adi.wnk.numdigits behave normally.

yes

defaulttone

integer

2

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

yes

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.

no

detectmode

integer

0

Type of incoming address signaling:
Value Definition
0 DTMF and dial pulse
2 MF

yes

waitforPCtime

ms

10000

The maximum time to wait for the PC to respond to an incoming call indication before playing a default tone (see defaulttone).

yes

ringontime

ms

1000

The length of each generated ring tone.

yes

ringofftime

ms

3000

The length of the silent interval between generated ring tones.

yes

busyontime

ms

500

The length of each generated busy tone.

yes

busyofftime

ms

500

The length of the silent interval between generated busy tones.

yes

reorderontime

ms

250

The length of each generated reorder (fast busy) tone.

yes

reorderofftime

ms

250

The length of the silent interval between generated reorder tones.

yes

wait1stdigittime

ms

7000

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

yes

waitfordigitstime

ms

8000

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

If an incoming call is detected with fewer digits than what is specified in the adi.wnk.numdigits parameter, ADIEVN_INCOMING_CALL is sent up to the host after this wait-for-digits timer has expired. At least one digit must be detected for this to occur.

yes

dtmfmask

mask

1000

A few flags to manage the reception of ANI digits.

· Bit 0 (&0x1). If set to 1, DTMF `#' symbolizes end of digit string

· Bit 1 (&0x2). If set to 1, DTMF `*' splits ANI and DID digits in the received digit stream

· Bit 2 (&0x4). If set, the ANI field comes before the '*'

yes

maxresourcetime

ms

9000

Maximum time to wait for a call setup resource to be available (AG Quad T with resource management only)

yes

noresourcemode

integer

0

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

yes

10.3.3 OGT Parameters (outbound wink start)
Field Name

Type/Unit

Default

Description

Changeable?

qualaddron

ms

50

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

no

qualaddroff

ms

50

Bit signaling qualification time for off-hook to on-hook transitions during call set-up.

no

qualdisconnect

ms

150

Bit signaling qualification time for off-hook to on-hook transitions after address signaling is completed.

no

qualpermsignal

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.

no

reserved

ms

0

Reserved.

no

mfflags

mask

3

Mask that controls behavior when using MF signaling. Set adistart.dial.method =2 so that adiPlaceCall uses MF digits. A value may be formed by ORing any of the following:
Value Definition
1 Begin with KP tone
2 End with ST tone

yes

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.

yes

minwinktime

ms

100

The minimum duration of a detected wink.

no

maxwinktime

ms

4900

The maximum duration of a detected wink.

no

predialtime

ms

70

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

no

mfkpstontime

ms

80

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

no

mfkpstofftime

ms

80

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

no

mfkpstampl

internal

352

Amplitude of dialed tones.

no

releaseguardtime

ms

1000

Minimum on-hook internal between calls.

yes

maxresourcetime

ms

10000

Maximum time to wait for a call setup resource to be available (AG Quad T with resource management only)

yes

10.3.4 FDI Parameters (Inbound Feature Group D)
Field Name

Type/Unit

Default

Description

Changeable?

qualaddron

ms

50

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

no

qualaddroff

ms

50

Bit signaling qualification time for off-hook to on-hook transitions during call set-up.

no

qualdisconnect

ms

150

Bit signaling qualification time for off-hook to on-hook transitions after address signaling is completed.

no

qualpermsignal

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.

no

reserved

ms

0

Reserved.

no

mfflags

mask

3

Mask that controls behavior when using MF signaling. Set adistart.dial.method =2 so that adiPlaceCall uses MF digits. A value may be formed by ORing any of the following:
Value Definition
1 Begin with KP tone
2 End with ST tone

yes

numdigits

count

12

The expected number of digits for incoming calls. If an incoming call is detected with fewer digits than what is specified in this parameter, ADIEVN_INCOMING_CALL is sent up to the host after the wait-for-digits timer (adi.wnk.waitfordigitstime) has expired. At least one digit must be detected for this to occur.

It is up to the application to parse the digit string and to decide whether or not to accept the call.

yes

defaulttone

integer

2

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

yes

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.

no

detectmode

integer

2

Type of incoming address signaling:
Value Definition
0 DTMF and dial pulse
2 MF

yes

waitforPCtime

ms

10000

The maximum time to wait for the PC to respond to an incoming call indication before playing a default tone (see defaulttone).

yes

prewinktime

ms

100

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

yes

ringontime

ms

1000

The length of each generated ring tone.

yes

ringofftime

ms

3000

The length of the silent interval between generated ring tones.

yes

busyontime

ms

500

The length of each generated busy tone.

yes

busyofftime

ms

500

The length of the silent interval between generated busy tones.

yes

reorderontime

ms

250

The length of each generated reorder (fast busy) tone.

yes

reorderofftime

ms

250

The length of the silent interval between generated reorder tones.

yes

wait1stdigittime

ms

7000

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

yes

waitfordigitstime

ms

8000

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

If an incoming call is detected with fewer digits than what is specified in the adi.wnk.numdigits parameter, ADIEVN_INCOMING_CALL is sent up to the host after this wait-for-digits timer has expired. At least one digit must be detected for this to occur.

yes

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.

yes

minwinktime

ms

100

The minimum duration of a detected wink.

no

maxwinktime

ms

4900

The maximum duration of a detected wink.

no

predialtime

ms

70

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

no

mfkpstontime

ms

80

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

no

mfkpstofftime

ms

80

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

no

mfkpstampl

internal

352

Amplitude of dialed tones.

no

releaseguardtime

ms

1000

Minimum on-hook internal between calls.

yes

preanswertime

ms

100

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

no

maxresourcetime

ms

10000

Maximum time to wait for a call setup resource to be available (AG Quad T with resource management only)

yes

noresourcemode

integer

0

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

yes

10.4 Special TCP Behavior

The following sections describe Operations specific to Wink Start-derived TCPs within the framework of Natural Call Control.

10.4.1 Inbound Calls: Retrieving Digits All at Once

With the Wink Start-derived TCPs, after ADIEVN_INCOMING_CALL is received, the calledaddr field in the ADI_CALL_STATUS structure usually contains all received digits. The callingaddr, usercategory and tollcategory fields are usually NULL.

This might change for the WNK0 TCP, digital two-way Wink Start, if there are ANI in the digit string. If the parameter ADI.WNK.dtmfmask is set correctly, the ANI digits are presented to the application in the callingaddr field.

The parameter ADI.WNK.numbdigits determines the number of digits the TCP should expect from the calling party (including ANI digits and the "*" symbol, when expecting ANI). The default is 3.

10.4.2 Inbound Calls: Retrieving Digits One at a Time

In general, digits are presented in the order in which they arrive. If ANI are present, the DTMF tones `*' and `#' are also present in the digits received by the TCP. Only the `*' (separator between ANI and DID) is passed to the application though, not the `#', that signals the end of the digit string (`ST' tone). When receiving digits one at a time, the application must know the order of the fields in the digit string (ANI or DID first).

10.4.3 Outbound Calls: Digit Format

Wink Start-derived TCPs expect the digit string to be formatted as follows:

d1 dn

If sending ANI digits is required, the digit string should be formatted as follows:

d1 dn * a1 an#

or:

a1 an * d1 dn #

By default category indicators are not used in Wink Start-derived TCPs.



(Page 1 of 1 in this chapter)


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