Detailed description of Data Call Setup

Last Updated : Sep 29, 2023 |

In addition to data-terminal and telephone dialing, the system accepts calls from other devices. For example, you can use a modular-processor data module (MPDM) that is equipped with an automatic-calling unit (ACU) interface module to dial from a host computer.

In addition to the numbers, the pound key (#), and the asterisk key (*) on a telephone, the table shows the special characters that a user can dial.

Table 1: Special characters

Character

Short description

Long description

SPACE or minus (-)

and

A space or a minus (-) improves legibility. The server ignores these characters during dialing.

plus (+)

wait

A plus (+) interrupts or suspends dialing until the user receives dial tone.

comma (,)

pause

A comma (,) inserts a 1.5-second delay.

percent (%)

mark

Use a percent (%) to indicate that the digits are for end-to-end signaling when you use a touchtone trunk. Use a percent (%) with a rotary trunk. The percent (%) is not required when you use a touchtone trunk.

UNDERLINE or BACKSPACE

-

Use an underline or a backspace to correct characters that you typed on the same line.

at (@)

-

Use an at sign (@) to delete the entire line and start again with a new DIAL prompt.

Each line of information that a user dials can contain 42 characters. Note that the system counts the plus (+) and the percent (%) as two characters each.

You administer the asynchronous data module (ADM) as one endpoint of a connection. The server establishes the connection at the scheduled time, and maintains the connection for the specified duration. After the call is accepted, the data set enters into continuous mode for the specified duration. If the server reboots during the connection, or if the connection drops, the server starts the connection again.

The system handles all ISDN basic rate interface (BRI) bearer data-call requests that are presently defined. If the server does not support a capability, the system returns a proper cause value to the terminal.

The system sends a cause code, also called a reason code, to BRI terminals to identify the reason that the system clears a call. The BRI data module converts some cause values to text messages for the system to display. In a passive-bus multipoint configuration, the system supports two BRI endpoints per port, and thus doubles the capacity of the BRI media module. When you change the configuration of a BRI endpoint from point-to-point configuration to a multipoint configuration, the original endpoint does not need to reinitialize. In a multipoint configuration, you can administer only endpoints that support service profile identifier (SPID) initialization.

The table shows the call progress messages and the call progress descriptions for digital communication protocol (DCP) and ISDN-BRI modules that the system provides.

Table 2: Call progress messages

Message Code

Module Type

Message Description

DIAL:

DCP

This message is the equivalent of a dial tone. Type the required number or the Feature Access Code (FAC), and then Press Enter.

CMD

BRI

This message is the equivalent of a dial tone. Type the required number or the FAC, and then Press Enter.

RINGING

DCP, BRI

This message is the equivalent of a ringing tone. The called terminal is ringing.

BUSY

DCP, BRI

This message is the equivalent of a busy tone. The called number is busy or out of service.

ANSWERED

DCP, BRI

The call is answered.

ANSWERED-NOT DATA

DCP

The call is answered, and the system does not detect a modem answer tone.

TRY AGAIN

DCP, BRI

This message is the equivalent of a reorder tone. The system facilities are unavailable.

DENIED

DCP, BRI

This message is the equivalent of an intercept tone. The system cannot place the call as dialed.

ABANDONED

DCP, BRI

The calling user abandoned the call.

NO TONE

DCP, BRI

The system does not detect a tone.

CHECK OPTIONS

DCP, BRI

The data-module options are incompatible.

XX IN QUEUE

DCP, BRI

XX represents the position of the call that is in the queue.

PROCESSING

DCP, BRI

The call is out of the queue. The facility is available.

TIMEOUT

DCP, BRI

The call exceeds the time that is allowed. The system terminates the call.

FORWARDED

DCP, BRI

This message is the equivalent of a redirection-notification signal. The called terminal activates Call Forwarding and receives a call, and the system then forwards the call.

INCOMING CALL

DCP, BRI

This message is the equivalent of ringing.

INVALID ADDRESS

DCP

The user entered a name that is not defined in the Alphanumeric Dialing feature.

WRONG ADDRESS

BRI

The user entered a name that is not defined in the Alphanumeric Dialing feature.

PLEASE ANS-

DCP, BRI

The originating telephone user used the One-Button Transfer to Data capability to transfer the call to a data module.

TRANSFER

DCP

Data Call Return-to-Voice is occurring.

CONFIRMED

DCP, BRI

This message is the equivalent of the confirmation tone. The system either accepts the feature request of the user, or the system sends the call to a local coverage point.

OTHER END

DCP, BRI

The endpoint terminates the call.

DISCONNECTED

DCP, BRI

The system disconnects the call.

WAIT

DCP, BRI

The normal process continues.

WAIT, XX IN QUEUE

DCP

The call is in a local hunt-group queue.

The following data functions are unavailable on ISDN-BRI telephones:

  • One-Button Transfer to Data

  • Return-to-voice

  • Data call preindication

  • Voice-call transfer to data

  • Data-call transfer to voice