Synopses & Reviews
The insider's guide to IP-based telephony: development, network deployment, testing, and beyond
Now that virtually every leading telecommunications service provider has committed to delivering IP-based telephony services, communications professionals face the enormous challenge of implementation. This hands-on guide brings together today's best-known answers and solutions for delivering Voice Over IP (VoIP) services with the quality customers demand. No other book covers the combined issues of protocol signaling, media transport methodology, reference topological considerations, and voice quality testing in service offerings. Bill Douskalis presents systematic coverage of every aspect of IP-based telephony:
- A realistic reference topology for implementing and benchmarking voice quality in IP telephony
- Detailed explanations of call setup using each major competing technology
- Signaling, bearer transport, and other key network elements
- In-depth network and service performance analysis in both "normal" and impaired scenarios
- State-of-the-art traces and performance measurements taken from actual IP networks
No matter what your role in delivering VoIP services, IP Telephony delivers the specifics you need to speed deployment, improve reliability, ensure quality, and simplify troubleshooting. Precise, thorough, and based firmly in the real world, it is simply indispensable.
Includes bibliographical references (p. 319-321) and index.
About the Author
Bill Douskalis has been designing, developing, deploying and troubleshooting network equipment and systems for over 20 years. He has worked extensively with a number of leading telecommunications companies, including AT&T Bell Laboratories' ACCULINK and Sprint's ION network.
Table of Contents
1. Protocols for Voice Over IP and Interactive Applications.
IP Telephony fundamentals. SGCP, MGCP and NCS—Overviews. H.323. An Overview of the ITU-T Approach for VoIP Telephony. SIP—Summary of Features of the Session Initiation Protocol.
2. Media Transport in Packet Networks.
RTP and RTCP—Definitions for Media Transport in IP Networks. RSVP The Resource Reservation Protocol. A Quick Look at AAL2 for Voice Transport. Edge Bandwidth Management—A Look at AAL2.
3. Basic Call Control for Voice Telephony.
An Overview of SS7. The Services of SSCP and TCAP. Call Control in Packet Networks. Heterogeneous Call Setup—Mapping SS7 to IP-Based Call Control. Closing Thoughts on Mixed Network Voice Telephony.
4. Metrics for Voice Quality.
Voice Quality in Converging TDM and IP Networks. Auditory Perception and Testing Methodologies. Perceptual Speech Quality Measurement. Voice Quality Test Instrumentation. Echo Measurement and Control. Summary.
5. A Simple Case Study in Measurements.
Objectives. From the Big Picture to the Lab. Equipment Setup and Configuration. Baseline Measurements. Testing with Connected Gateways. Observations and Conclusions.
6. Voiceband Call Considerations— A Detailed Look at Fax.
A Look at a Real-Time Trace of the T.30 Protocol. Fax over Packet Networks. Real-Time Internet Fax—T.38. Basics of V.34 Fax. Group 3 Fax Error Correction Mode (ECM). Voiceband Data Transport Revisited—AAL2. Summary of the Fax Discussion and Possible Issues. References.