XML Based Service Provisioning in Converged Voice and Data Networks

Diploma Thesis , 2001 , 77 Pages , Grade: 1,7

Electrotechnology

In today’s world, there are mainly two types of communication networks: circuitswitched networks and packet-switched networks. The current telephone networks are mostly based on the circuit-switched networks, whereas the Internet is mainly based on the packetswitched networks, which are also called IP networks. However, there is a strong tendency to combine both of these networks, which points to the direction that the IP networks are going to replace services provided by current telephone networks. This would eventually mean that IP networks might replace the telephone networks, in the future.
Following are some reasons why IP networks seem to replace the circuit-switched
networks:
· First of all, the IP networks provide cheaper communication. Considering that
the Internet access is nearly free, the cost advantage of IP networks gets clearer
[25].
· Secondly, IP networks provide the ability of integrating the data and voice
applications, and even some other applications, like video-conferencing,
integrated voice mail, e-mail, and the like [26].
· Another important reason is that IP networks allow open implementation of
end systems. With a reasonable programming knowledge everybody could
implement an end system for IP networks. In the classical telephony end users
cannot implement any end system, but have to use whatever provided by the
service providers. [27]

Inhaltsverzeichnis (Table of Contents)

• Preface
• List of Abbreviations
• Table of Contents
• 1 Introduction
• 2 Fundamentals
  • 2.1 Extensible Markup Language (XML)
    • 2.1.1 XML Overview
    • 2.1.2 XML Specifications
      • 2.1.2.1 Document Type Definition (DTD)
      • 2.1.2.2 Well-Formed XML Documents
      • 2.1.2.3 Valid XML documents
    • 2.1.3 How XML works
    • 2.1.4 SGML
    • 2.1.5 HTML
    • 2.1.6 XML vs. HTML
  • 2.2 Session Initiation Protocol (SIP)
    • 2.2.1 SIP Characteristics
    • 2.2.2 SIP Basics
    • 2.2.3 SIP Addresses
    • 2.2.4 SIP Messages
    • 2.2.5 SIP Operation
  • 2.3 Intelligent Networks (IN)
    • 2.3.1 IN Architecture
    • 2.3.2 Benefits of Intelligent Networks
    • 2.3.3 IN Services
• 3 Call Processing Language (CPL)
  • 3.1 Language Specifications
    • 3.1.1 Top Level Actions
    • 3.1.2 Switches
    • 3.1.3 Location Modifiers
    • 3.1.4 Signaling Actions
    • 3.1.5 Non-signaling actions
    • 3.1.6 Subactions
  • 3.2 Examples
    • 3.2.1 Example 1: Simple call forwarding
    • 3.2.2 Example 2: A more complicated example
  • 3.3 Extensibility
• 4 Architecture
  • 4.1 SIP User
  • 4.2 SIP Server
  • 4.3 Location Database
  • 4.4 CPL Engine
    • 4.4.1 Design
    • 4.4.2 Flow diagram
    • 4.4.3 Tag Classes
  • 4.5 CPL Repository
    • 4.5.1 Flat File vs. Database
      • 4.5.1.1 Flat File
      • 4.5.1.2 Database
    • 4.5.2 Active vs. Passive Repository
  • 4.6 CPL User Editor
  • 4.7 The relations of the components
• 5 Tools used in the project
  • 5.1 XML Parser
    • 5.1.1 Document Object Model (DOM)
    • 5.1.2 Simple API for XML (SAX)
    • 5.1.3 DOM vs. SAX
  • 5.2 Common Object Request Broker Architecture (CORBA)
    • 5.2.1 History of Distributed Systems
    • 5.2.2 Alternatives of CORBA
      • 5.2.2.1 Socket Programming
      • 5.2.2.2 Remote Procedure Call (RPC)
      • 5.2.2.3 OSF Distributed Computing Environment (DCE)
      • 5.2.2.4 Microsoft Distributed Component Object Model (DCOM)
      • 5.2.2.5 Java Remote Method Invocation (RMI)
    • 5.2.3 Advantages of CORBA
    • 5.2.4 The TAO CORBA
    • 5.2.5 The Naming Service
    • 5.2.6 The Event Service
  • 5.3 Lightweight Directory Access Protocol (LDAP)
• 6 Implementation
  • 6.1 SIP Server
  • 6.2 CPL Engine
    • 6.2.1 General overview
    • 6.2.2 CORBA Interface
    • 6.2.3 Classes
  • 6.3 CPL Repository
  • 6.4 CPL User Editor

Zielsetzung und Themenschwerpunkte (Objectives and Key Themes)

This master thesis investigates the design, implementation, and evaluation of creating additional services for Internet Telephony using the Extensible Markup Language (XML) as the data definition format. The main goal is to use the Call Processing Language (CPL) to create intelligent services for Internet Telephony, providing features such as call forwarding, redirection, and e-mail notifications.

• The development of a Call Processing Language (CPL) to provide intelligent services for Internet Telephony.
• The application of Extensible Markup Language (XML) as a foundation for creating these services.
• The integration of Session Initiation Protocol (SIP) as the signaling protocol for Internet Telephony.
• The comparison of the proposed system with current Intelligent Network (IN) solutions used in traditional telephony.
• The evaluation of the ease of implementation and user-friendliness of the CPL environment.

Zusammenfassung der Kapitel (Chapter Summaries)

• Chapter 2: Fundamentals: This chapter introduces the essential concepts of Extensible Markup Language (XML) and Session Initiation Protocol (SIP), highlighting their importance in Internet Telephony. It also discusses the Intelligent Networks (IN) used in traditional telephony as a reference point for comparison with the proposed system.
• Chapter 3: Call Processing Language (CPL): This chapter presents a detailed explanation of the Call Processing Language (CPL), which utilizes XML to define and control Internet Telephony services. It covers language specifications, including tags for different actions, switches, location modifiers, and signaling actions. Two examples illustrate the use of CPL for simple and complex call forwarding scenarios.
• Chapter 4: Architecture: This chapter outlines the architecture of the system, consisting of six main components: SIP User Agent, SIP Server, Location Database, CPL Engine, CPL Repository, and CPL User Editor. It focuses on the design and implementation details of the CPL Engine and CPL Repository, highlighting their crucial role in the system.
• Chapter 5: Tools used in the project: This chapter discusses the tools used in the project, particularly the XML parser and CORBA (Common Object Request Broker Architecture), which are essential for parsing CPL scripts and establishing communication between the CPL Engine and SIP Server. Additionally, a brief explanation of LDAP (Lightweight Directory Access Protocol) is provided.
• Chapter 6: Implementation: This chapter provides information about the implementation of each component in the system, including modifications made to the existing SIP Server and the detailed implementation of the CPL Engine, CPL Repository, and CPL User Editor.

Schlüsselwörter (Keywords)

This thesis explores the application of XML-based service provisioning, specifically using the Call Processing Language (CPL) for Internet Telephony. The main focus is on creating and evaluating intelligent services for end users. This includes aspects like call forwarding, redirection, and integration with other communication channels. The project utilizes Session Initiation Protocol (SIP) as the signaling protocol, and the architecture relies on CORBA (Common Object Request Broker Architecture) for communication between components.

• College: University of Ulm
• Grade: 1,7
• Author: Sertac Cetiner (Author)
• Publication Year: 2001
• Pages: 77
• Catalog Number: V81280
• ISBN (eBook): 9783638013451
• ISBN (Book): 9783638917049
• Language: English
• Tags: Based, Service, Provisioning, Converged, Voice, Data, Networks