lapddemo overview

lapddemo establishes a data link and sends and receives Q.931 messages. It demonstrates how:

Messages built and sent with this demonstration program are based on standard Q.931 specifications (Blue Book) and may not be accepted or allowed in some switch variants.

Featured functions

isdnReleaseBuffer, isdnSendMessage, isdnStartProtocol, isdnStopProtocol

Requirements

Usage

lapddemo [options]

where options are one or more of the following:

Option

Meaning

Defaults

-b boardno

Number of the board to use. (Board numbers are specified in the board keyword file.)

0

-n

lapddemo configured for the network terminator (NT) side.

Not specified. lapddemo is configured for terminal equipment (TE).

-a nai

Network access identifier (NAI).

None.

-g nfas_group

NFAS group number, for duplicate NAI values.

None.

-v verboselevel

Verbosity level. Valid values are:

0: Show no messages

1: Show SETUP messages only

2: Show all ISDN messages

2

-f filename

Name of the configuration file to be read. This file describes the behavior of the program in terms of what Q.931 messages are sent or received.

Specifications for outgoing calls are not given in the default configuration file. You must make additions to this file in order for the demonstration program to achieve the CONNECTED state for outbound calls.

lapddemo.cfg


Functional overview

When lapddemo is run, it performs the following tasks:

Task

Description

1

It parses command-line arguments and makes sure all arguments are valid and do not conflict.

2

It initializes Natural Access.

3

It starts the ISDN protocol stack on the board specified on the command-line, either as terminal equipment (TE) or as network equipment (NT), with the specified network operator variant and country variant.

4

It sends a SABME message on the trunk to establish the data link.

5

If you type S, the program sends a SETUP message to the trunk. Otherwise, it waits for messages from the line.

6

If a Q.931 message is received, the program decodes information from the message and responds with an appropriate message, specified in the configuration file. For example, after receiving a SETUP message, it may send an ALERTING message.