Voice over IP

著者

書誌事項

Voice over IP

Uyless Black

Prentice Hall PTR, c2000

大学図書館所蔵 件 / 全4件

この図書・雑誌をさがす

注記

Includes bibliographical references (p. 317-319) and index

内容説明・目次

内容説明

2246C-4 The authoritative guide to Internet telephony *Managing and optimizing the performance of IP voice networks *Configuring IP-based call centers *Internetworking IP with SS7 Uyless Black has written the essential guide for telecommunications professionals who must understand voice-over-IP (VoIP)-or deploy it. Clearheaded and free of hype, Voice Over IP carefully evaluates both VoIP's challenges and its compelling advantages, and then reviews each technical standard and critical issue associated with successful deployment. Start by reviewing the key Internet and IP characteristics that make VoIP difficult, including packet loss and variable delay. Next, understand the role of digital signal processors (DSPs) and voice coders in VoIP. Learn how to establish paths to service providers through the local loop via ISDN, xDSL, HFC, or other approaches; review modem technology for VoIP applications; and understand today's key Internet telephony protocols. Coverage includes: *Integrating total VoIP solutions: DSPs, voice coders, high-speed modems, gateways, local loop connectivity, and more *The role of VoIP gateways and gatekeepers *Internetworking SS7 with IP and H.3 23 *VoIP supporting protocols for multicasting (IGMP and MBONE), bandwidth reservation (RSVP, RTP, RTCP), and security services Black describes today's best approaches for managing performance in both private and public IP networks, compares VoIP with packet voice alternatives such as Voice over Frame Relay (VoFR) and Voice over ATM (VoATM), and more. You'll also find convenient references to telephony signaling, ISDN and SS7, and V.90 modems. Every telecommunications professional will be impacted by the VoIP revolution. Whether you're evaluating or deploying VoIP, this book places a world-class telecom consultant at your side, delivering all the objective information and insight you need to succeed.

目次

1. Introduction. Internet Telephony and Packetized Voice. Why Internet Telephony? Why Use IP for Telephony Traffic? Barriers to Successful Deployment of IP Telephony. VoIP in the Internet and in Private Internets. The Question: Not If, But How? Configuration Options. Private VoIP Networks. The Next Step. E-com and IP-based Call Centers. Configuration and Topology Choices. Basic Terms and Concepts. Attributes of the Internet. The Internet Layered Architecture. Evaluating the Factors in Packetized Voice. Accommodating to the Voice and Data Requirements in a Network. Making the Internet Look Like the Telephone Network. Summary. 2. Characteristics of the Internet & IP. Architecture of an Internet. ISPs and the Telephone Network. Attributes of the Internet. Packet Loss. Need for Fixed Routing? Size of Packets and Kinds of Traffic IP Supports. Overview of IP. TCP and UDP. Summary. 3. Digital Signal Processors (DSPs). Role of DSPs in Packet-Voice Operations. DSP vs. Customized Hardware. Fixed- and Floating-Point Processors. Memory Architectures. The Software is Different. Fast Fourier Transform (FFT) Operations. Signal Filters and the Finite Impulse Response (FIR) Filter. Predictability of Performance. Another Example of DSP Code. Coming Up. Summary. 4. Voice Coders. Functions of the Voice Coder. Classification of Speech Coders. Linear Prediction Analysis-by-Synthesis (LPAS) Coders. Parameter Speech Coders: 2.4-kbit/s Mixed-Excitation LPC (MELP). Evaluating Coders. Comparison of Speech Coders. Summary. 5. Connecting to Service Providers through the Local Loop. Path between an Internet User and the Internet. The Bandwidth Problem at the Local Loop. Terminating the Modem Analog Signal. Alternatives to the Modem-based Local Loop Access. The Integrated Services Digital Network (ISDN). Role of Digital Subscriber Line (DSL) Technologies. The Hybrid/Fiber Coax (HFC) Approach. A High-Speed Proprietary Solution. Bypassing the Circuit-Switched Technology to Reach the Internet. Summary. 6. Modems, LAPM, PPP, and the V.100 Series. Another Look at the Layered Architecture for VoIP. Prevalent Modems. Role of DSPs in the Modem's Operations. Typical Layout. The EIA-232 Interface. Typical Layout for the Modem. Role of the Point-to-Point Protocol (PPP). The Protocol Data Unit on the Link Between the User and the ISP. V-Series Modems. The 56 kbit/s Modem (V.90). The V.110 and V.120 Recommendations for ISDN Interfaces. Summary. 7. Putting the Pieces Together. Yet Another Look at the Layered Architecture for VoIP. Steps to the Exchange of VoIP Traffic. Another Look at the VoIP Protocol Suite. The VoIP Tunnel. Undue Processing Overhead. Summary. 8. Performance Considerations. Packet Size, Buffer Size, Loss, and Latency. Performance of VoIP in Private Systems. Performance of VoIP in Public Systems. Summary. 9. VoIP Gateways and Gatekeepers. The Gateway/Gatekeeper Model. The H.323 Specification. Architecture of H.323. Codec Requirements. The H.323 Protocol Stack. Registration, Admissions, and Status (RAS) Operations. Other RAS Procedures. Some Comments on H.323 and H.225.0. Summary of H.323. Media Gateway Control Protocol (MGCP). Other Protocols. Call Agents and Calls. Relationship to H.323. Endpoints, Connections, Calls, Events, Packages, and Names. The Connection Modes. MGCP Commands: For the API and the Messages. The MGCP Parameters. API Commands and Associated Parameters. MGCP Messages and Associated Parameters. Messages and Message Parameters. Examples of MGCP Operations. Summary. 10. Internetworking SS7 with IP and H.323. Why Combine IP and SS7? Possible Configurations. The Basic Framework and the Internet Specifications. Taking Advantage of SS7 Capabilities. The SS7-IP Architectural Framework. The Reliable Signaling Gateway Protocol (RGSP). Messages and Q.931 Mappings. Interworking H.323 and SS7. Proposal for an Adaptation Layer. Summary. 11. Other VoIP Supporting Protocols. IGMP and MBONE. RSVP. RTP. RTCP. Network Time Protocol (NTP). Security Services. DIAMETER. IPDC. DiffServ. Label-Swapping Protocols. Summary. 12. Other Packet Voice Alternatives. Voice over Frame Relay (VoFR). Service Multiplexing. VoFR. Voice over ATM (VoATM). VoFR and VoATM: Partners with or Competitors to VoIP? Layer 3 Switching. Summary. Appendix A: Telephony Signaling. Appendix B: ISDN and SS7. Appendix C: Tutorial on the V.34 and V.90 Modems. Index.

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