IP Telephony
Deploying Voice-over-IP Protocols

Provides a comprehensive practical overview of the technology behind Internet Telephony, giving essential information to network engineers, designers and managers who need to understand the protocols. This book also explores the issues involved in migrating from the telephony infrastructure to an IP-based real time communication service.

"IP Telephony: Deploying Voice-over-IP Protocols": assumes a working knowledge of IP and networking and addresses the technical aspects of real-time communication over IP; presents a high level overview of packet media transport technologies, covering all the major VoIP protocols - SIP, H323 and MGCP; details specific strategies to design services for public networks, where endpoints cannot be trusted and can be behind firewalls; and explores the problems that may arise from incomplete protocol implementations, or architectures optimized for private networks which fail in a public environment. This amply illustrated, state-of-the art reference tool will be an invaluable resource for all those involved in the practical deployment of VoIP technology.

Abbreviations.
Glossary.
Practice.
1.

Voice over Packet.
1.1
Transporting voice, fax and video over a packet network.
1.2
Encoding media streams.
2.

H.323: Packet--based Multimedia Communications Systems.
2.1
Introduction.
2.2
H.323 step by step.
2.3
Optimising and enhancing H.323.
2.4
Conferencing with H.323.
2.5
Directories and numbering.
2.6
H.323 Security.
2.7
Supplementary services.
2.8
Future work on H.323.
3.

The Session Initiation Protocol (SIP).
3.1
The origin and purpose of SIP.
3.2
From RFC 2543 to RFC 3261.
3.3
Overview of a simple SIP call.
3.4
Call handling services with SIP.
3.5
Instant messaging and presence.
3.6
SIP security.
3.7
SIP and H.323.
4.

The Media Gateway to Media Controller Protocol (MGCP).
4.1
Introduction: why MGCP?
4.2
MGCP 1.0.
4.3
Sample MGCP call flows.
4.4
The future of MGCP 63.
5.

Advanced Tpoics: call Redirection.
5.1
Call redirection to VoIP networks.
6.

Advanced Topics: NAT Traversal.
6.1
Introduction to Network Address Translation.
6.2
Workarounds for VoIP when the network cannot be controlled.
6.3
Recommended network design for service providers.
6.4
Conclusion.
Annex.
Index.