# 4 EXS API Application Development

Purpose

This chapter presents an overview of the software architecture and the application requirements for non-SwitchKit users.

In this section:

Note to SwitchKit Users

Configuration Guidelines

The Core Message Set

API Message Guidelines

Configuring the CSP

Network Synchronization

Line Card Redundancy

Channel Configuration

Service State

Reconfiguration Considerations

Application Requirements

Host Connection Module

Communication Module

Message Management Module

Call Processing Module

Preprogrammed Instructions

Configuration Module

Alarm Manager Module

Real-Time Logging Module

User Interface Module

Host Communication Module

IP Address

System Maintenance

Host Link Failure Detection

Message Resend Logic

System Busy Warning and System Busy Alarm

Reports

PPL Auditing

Line Card Overload Logic

Line Card Overload Logic Actions

Loopback Diagnostics