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Chapter 3

Fusion API Summary

3.1 Introduction

: 3.1.1 CT Access
: 3.1.2 TX Series

3.2 CT Access

: 3.2.1 CT
: 3.2.2 ADI
: 3.2.3 CT Access Switching
: 3.2.4 AG TRAU
: 3.2.5 HBF
: 3.2.6 Voice Message

3.3 TX Series API's

: 3.3.1 CPI (Communication Processor Interface)
: 3.3.2 Loader
: 3.3.3 Common Management
: 3.3.4 TelePathX (TPX)
: 3.3.5 Virtual Port Data Transfer/Configuration
: 3.3.6 RTP/RTCP

3.4 H.323 Stack API

3.1 Introduction

Fusion uses a a variety of APIs to perform operations that use AG board and TX board resources. Gateway applications use: CT Access services for controlling the PSTN interface and performing data conversion. TX Series API functions for controlling the flow of data to and from the packet network interface. H.323 stack API functions (optional) for performing IP/LAN session control at the packet network interface.
Figure 8 illustrates how gateway applications use functions from these APIs to control the flow of data between PSTNs and packet networks. Figure 8. Fusion CT Access, TX Series, and H.323 Stack APIs
This chapter provides a brief summary of the CT Access, TX Series, and H.323 stack APIs.

3.1.1 CT Access Services

Fusion gateway applications use the following CT Access services: ADI service Switching service AG TRAU service HBF service (optional) Voice Message service (optional)

3.1.2 TX Series APIs

Fusion gateways use functions from the following TX series APIs: CPI Library TX Loader API Common Management API TelePathX API Virtual Port Data Transfer/Configuration API RTP/RTCP API
An optional H.323 stack API is also available for performing call control at the packet network interface.

3.2 CT Access

CT Access provides a standard programming interface for executing telephony functions. CT Access supports both single-threaded and multi-threaded programming models, and also provides several subsets of telephony functions grouped into services. Figure 9. CT Access APIs
The sections that follow provide a brief description of the CT Access service APIs. Refer to Chapter 4 of this manual for more information about how Fusion gateway applications use functions from these APIs.
CT Access provides functions for: Initializing the application environment Initializing CTA contexts Processing events Handling errors Managing parameters Integrating and executing services
Applications must initialize CT Access before they can use any functions from CT Access or its associated services. Refer to the CT Access Developer's Reference Manual for more information about specific CT Access functions .

3.2.1 ADI Service

The ADI service provides all AG board-level functionality for CT Access. It includes functions for: Performing call control Enabling and disabling DTMF detection Performing DTMF collection and generation Monitoring call progress Detecting and generating tones
Refer to the ADI Service Function Reference Manual for more information about specific ADI service functions.

3.2.2 CT Access Switching Service

The CT Access Switching service provides a set of functions for controlling Multi-Vendor Integration Protocol (MVIP) switching. It includes functions for: Opening and closing switch handles Making and breaking switch connections
Refer to the CT Access Switching Service Developer's Reference Manual for more information about specific Switching service functions.

3.2.3 AG TRAU Service

The AG TRAU service provides a group of functions for controlling TRAU programs that run on AG RealTime (AG-RT) daughterboards. It includes functions for: Loading and unloading AG TRAU programs to AG-RT daughterboard DSPs Attaching and detaching AG TRAU channels to CTA contexts Enabling and disabling AG TRAU processing on specific channels (performing data conversion) Retrieving information about AG TRAU channels and AG-RT DSPs Registering call-back routines for Host-based programs
Refer to the Fusion AG TRAU Developer's Reference Manual for more information about specific AG TRAU functions.

3.2.4 HBF Service

Fusion gateway systems that use standard network interface cards (instead of TX Series boards) use a CT Access service called the Host-based Fusion (HBF) service. The HBF service provides function for the following. Establishing connection points (or endpoints) for transferring data between different points on the gateway. Associating pairs of endpoints to form channels for transferring voice data.
Refer to the Host-based Fusion Service Developer's Reference Manual for more information about the Host-based Fusion gateway programming model and specific HBF service functions.

3.2.5 Voice Message Service

Voice Message service functions work in conjunction with the ADI service functions to play and record voice messages. The service includes functions for: Playing message prompts from files or from memory Recording and editing voice messages in files or from memory
Refer to the Voice Message Service Developer's Reference Manual for more information about specific Voice Message service functions. Refer to the ADI Service Function Reference Manual for information about ADI service playing and recording functions.

3.3 TX Series API's

The TX Series APIs allow gateway applications to configure and control processes running on TX boards. These APIs use the Communications Processor Interface (CPI) Library to access TX board-level resources.
Fusion gateways use the TPX API, Virtual Port APIs, and RTP/RTCP APIs to establish sessions and control the flow of data to private LAN networks and the Internet.
The sections that follow provide a brief description of the TX series APIs that Fusion gateway applications use to control the packet network interface. Chapter 5 provides more specific information about how Fusion gateway applications use functions from these APIs. Figure 10. TX Series APIs

3.3.1 CPI (Communication Processor Interface) Library

Applications on the host PC communicate to processes on the TX board through communications channels to the TX board. A low-level interface to these channels is provided by the Communications Processor Interface Library (CPI Lib).
The CPI library provides functions for: Initializing the CPI library Opening and closing channels to processes running on TX boards Sending packets to open channels Returning wait objects for specific handles
Refer to the TX Series CPI Library Software Interface Guide for more information about specific Communication Processor Interface library functions.

3.3.2 Loader API

The Loader API allows host-based applications to tailor the operating environment of the TX board to their requirements.
The Loader API includes functions for: Initializing the Loader library Loading and configuring processes on TX series boards
Refer to the TX Series Loader Application Program Interface Guide for more information about specific Loader API functions.

3.3.3 Common Management API

The Common Management API enables gateway applications to configure, control, and examine embedded TX board tasks. As Figure 10 shows, the TPX API uses the Common Management API to communicate with the TX board. This architecture facilitates communication to and from the TX board and insulates applications from complex messaging syntax.
The Common Management API includes functions for: Configuring and controlling processes running on TX boards Examining the behavior of processes executing on the TX boards
Refer to the TX Series Application Program Interfaces Common Management Guide for more information about specific Common Management API functions.

3.3.4 TelePathX (TPX) API

The TPX API configures and performs IP packet routing between the TX board and various network interfaces. The API also lets applications configure routing for the TX board.
The TPX API provides functions for: Configuring, controlling, and monitoring TPX routes Creating and deleting route definition packets and specifying IP address information Setting up Ethernet interfaces
Refer to the TX Series TelePathX (TPX) Application Program Interface Program Interface Guide for more information about specific TPX API functions.

3.3.5 Virtual Port Data Transfer/Configuration API

Virtual ports provide a way of allocating TX board resources for processing specific channels of data. In Fusion gateway applications, these channels carry streams of audio data coming from the PSTN interface.
Fusion gateway applications use virtual ports to receive the encoded framed data processed by AG TRAU programs running on AG-RT daughterboards. Because data sent from the AG-RT daughterboards to TX boards is often multiplexed (several channels of data is sent on a single MVIP stream), virtual ports often need to de-multiplex the data when they receive it.
The Virtual Port Data and Configuration APIs provide functions for: Initializing the Virtual Port API Assigning and destroying TX board resources for virtual ports Configuring and modifying virtual ports Monitoring the status of existing virtual ports
Refer to the TX Series Virtual Port Data Transfer Application Program Interface Guide for information about functions for configuring and controlling virtual ports. Refer to the TX Series Virtual Port TDM Configuration Guide for information about setting up virtual ports based on specific application requirements.

3.3.6 RTP/RTCP API

RTP and RTCP protocols identify standards for controlling the transmission of real time audio and video data to and from packet switched networks. These APIs provide data and control streams that allow applications to control the timing and synchronization of audio and video data sent over IP networks.
The RTP and RTCP APIs provide functions for: Associating voice channels carried on MVIP streams with RTP sessions running on TX boards Determining the type of data in RTP packets Formatting RTP/RTCP control packets Retrieving status and data from response or notification packets Managing latency of data sent in RTP sessions (using the Fusion application jitter buffer)
Refer to the TX Series RTP/RTCP Developer's Guide for more information about specific RTP and RTCP API functions.

3.4 H.323 Stack API

Fusion gateway applications require a mechanism for maintaining IP call control and for managing IP data transport. The call management module can be designed based on proprietary call control schemes, or based on H.323 protocol specifications. The Fusion application development kit provides an optional H.323 protocol stack API for building H.323 compliant IP Call Control Modules.
The Fusion H.323 stack includes functions for: Controlling calls placed or received through the gateway's packet network Establishing calls and negotiating capabilities between remote hosts
For more information about specific H.323 stack API functions, refer to the Fusion H.323 Stack Programmer's Guide and Reference. Note: The H.323 stack is a mandatory component of Host-based Fusion gateways. For more information about the role of the H.323 stack in Host-based Fusion gateways, refer to the Host-based Fusion Developer's Reference Manual.

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