Packet Guide to Voice over IP. A system administrator's guide to VoIP technologies (e-book)

Packet Guide to Voice over IP. A system administrator's guide to VoIP technologies (e-book) - Opis

Go under the hood of an operating Voice over IP network, and build your knowledge of the protocols and architectures used by this Internet telephony technology. With this concise guide, you...ll learn about services involved in VoIP and get a first-hand view of network data packets from the time the phones boot through calls and subsequent connection teardown.With packet captures available on the companion website, this book is ideal whether you...re an instructor, student, or professional looking to boost your skill set. Each chapter includes a set of review questions, as well as practical, hands-on lab exercises.Learn the requirements for deploying packetized voice and videoUnderstand traditional telephony concepts, including local loop, tip and ring, and T carriersExplore the Session Initiation Protocol (SIP), VoIP...s primary signaling protocolLearn the operations and fields for VoIP...s standardized RTP and RTCP transport protocolsDelve into voice and video codecs for converting analog data to digital format for transmissionGet familiar with Communications Systems H.323, SIP...s widely used predecessorExamine the Skinny Client Control Protocol used in Cisco VoIP phones in networks around the world Spis treści:
Packet Guide to Voice over IP
Preface
Audience
Contents of This Book
Conventions Used in This Book
Using Code Examples
Safari Books Online
How to Contact Us
Acknowledgments
Dedication
1. Introduction to Voice over the Internet Protocol
What Is VoIP?
Real-time Versus Nonreal-time Data
Why Change to (...) więcej VoIP?
The Business Case
VoIP and FCC Regulation
911
A Note on Power
General VoIP Topologies
Power over Ethernet
PoE Basic Operation
VoIP Protocols
Signaling Protocols
Session Initiation Protocol
H.323
Skinny Client Control Protocol
Transport Protocol
VoIP Basic Operation
Performance
Unified Communications
Summary
Standards and Reading
Review Questions
Review Question Answers
Lab Activities
Activity 1Review of the Standards
Activity 2Download Wireshark and the Capture Files for This Chapter
Activity 3Examine VoIP Offerings in Your Area
Activity 4Take a Look at the FCC Website
Activity 5Latency, Packet Loss, and Jitter
2. Traditional Telephony
Introduction
Overview
Organizations
Connecting to the Traditional World
Telecommunication Companies
Telephone Wiring
Data Cabling, EIA568 A and B
POTS and the Local Loop
T-1
T-1 signaling
T-1 physical layer and wiring
Integrated Services Digital Network
Basic Telephone-Call Operation
Summary
Standards and Reading
Review Questions
Review Question Answers
Lab Activities
Activity 1Review Your Local Telephone Connections
Activity 2Experiment with the Desktop Telephone or VoIP Phone
Activity 3Wiring to the PBX or Central Office
Activity 4ITU-T Recommendations
3. Session Initiation Protocol
Introduction
Protocol Description
Components
Addressing
Basic Operation
SIP Messages and Message Structure
Requests
Responses
Header Fields
Basic Operation Continued
Session Description Protocol (SDP)
Trunks
Security
Summary
Standards and Reading
Review Questions
Review Question Answers
Lab Activities
Activity 1Build the Topology Shown
Activity 2Packet Capture
Activity 3Packet Capture Analysis
Activity 4Phone-Call Analysis
Activity 5SDP
4. The Real-Time Transport Protocol and the Real-Time Control Protocol
Protocol Description
Profiles
Basic Operation
Protocol Structure
Header first octet
Header second octet
Packet fields beyond the first two octets
RTP extension header
RTP Control Protocol
Detailed Operation
Security
Vectors
SRTP Operation
Summary
Standards and Reading
Review Questions
Review Answers
Lab Activities
Activity 1Topology Build
Activity 2Analysis of the RTP Stream
Activity 3The Codec
Activity 4Analysis of the RTCP Stream
5. Codecs
Audio Frequencies
Voice Signals
Audio Coders and Decoders
Sampling
Quantizing
ITU-T G Series Specifications
Codec Selection and Performance
So, what values can we expect?
Transcoding
Packet Loss and Packet Loss Concealment (PLC)
What Codec Are You Using?
Video Signals
Sending a Series of Pictures
Video Encoding
Standards Groups for Video
Profiles
ITU-T Video Recommendations
ISO/IEC Video Standards
Summary
Standards and Reading
Review Questions
Review Question Answers
Lab Activities
Activity 1Colors
Activity 2File Sizes
Activity 3Audio Quality
Activity 4Video Quality
6. H.323 ITU-T Recommendation for Packet-Based Multimedia Communications Systems
Recommendation Description
Subprotocols
Basic Operation and Message Structure
H.225 Messaging
Q.931 Fields
H.225 Message Format
H.225 RAS
H.225 RAS fields
H.225 Standard Messages
H.225 Modes
FastStart
Other H.225 Messages
H.245
Voice Data
Termination
Summary
Standards and Reading
Review Questions
Review Question Answers
Lab Activities
Activity 1Build the Topology Shown
Activity 2Capture Setup
Activity 3Packet Capture Analysis
Activity 4Phone-Call Analysis
Activity 5H.245
7. Skinny Client Control Protocol
Protocol Description
Structure
Basic Header Format
Topology Construction
Operational Stages
Startup
Registration
Picking up the HandsetGoing Off-Hook
Dialing a Number
At the Receiver
Back at the Source Phone
Voice Data
Teardown of the Call
Performance Measuring
Off-Site Calling
Summary
Reading
Review Questions
Review Answers
Lab Activities
Activity 1Basic Topology Build
Activity 2Going Off-Hook
Activity 3Show and Debug
Activity 4Call-Flow Diagram
Activity 5Multiple Call Managers
About the Author
Colophon
Copyright mniej