Asterisk 1.4 - The Professional's Guide. Implementing, Administering, and Consulting on Commercial IP Telephony Solutions Racibórz

Asterisk is the leading Open Source Telephony application and PBX software solution. It represents an effective, easy-to-administer, and accessible platform for running enterprise telephony requirements. The real world, however, offers numerous hurdles when running Asterisk in the commercial environment including call routing, resilience, or integrating Asterisk with other systems. This book will show you some of the ways to overcome these problems.As the follow-up to Packt's highly successful 2005 title Building Telephony Systems with Asterisk, this book presents the collected wisdom of Asterisk Professionals in the commercial environment.Aimed at Administrators and Asterisk Consultants who are comfortable with the basics of Asterisk operation and installation, this book covers numerous hands-on topics such as Call Routing, Network Considerations, Scalability, and Resilience ñ all the while providing practical solutions and suggestions. It also covers more business-related areas like Billing Solutions and a Winning Sales Technique. Even if your interest or experience with Asterisk is lower level, this book will provide a deeper understanding of how Asterisk operates in the real world.Asterisk is deployed across countless enterprises globally. Running on Linux, it has constantly demonstrated its resilience, stability, and scalability and is now the advanced communication solution of choice to many organizations and consultants.With a foreword from Mark Spencer, the man behind Asterisk, this book presents the accumulated wisdom of three leading Asterisk Consultants and shows the reader how to get the most out of Asterisk in the commercial environment. Over the course of eleven chapters, this book introduces the reader to topics as diverse as Advanced Dial Plans, Network Considerations, and Call Routing, through to Localization, DAHDI, Speech Technology, and Working with a GUI. The book also covers the more nebulous aspects of being an Asterisk professional such as evaluating customer requirements and pitching for contracts.This book represents the wisdom and thoughts of front line consultants. The knowledge they impart will prove informative, thought provoking and be of lasting interest to Asterisk professionals. Spis treści: Asterisk 1.4 Table of Contents Asterisk 1.4 Credits Foreword About the Authors About the Reviewers Preface Reviewing the basics No compromise What this book covers Onwards Conventions Reader feedback Customer support Downloading the example code for the book Errata Piracy Questions 1. The Dialplan Dialplan location Extensions and contexts Pattern matching Why use contexts? Call barring made simple Time and day call routing Variables Inheritance of channel variables through the dialplan Using the AstDB Dialplan features and additions func_devstate What can we use the DEVSTATE() function for? Outgoing trunk selection Calling extensions Setting lights Boosting outgoing call capacity Using multiple broadband lines Configuration overview Setting up the routing in Linux Configuring Asterisk Explanation of the macro Downsides System() application Summary 2. Network Considerations when Implementing Asterisk Centralized and distributed installations Centralized installations Distributed solutions Latency and jitter Jitterbuffer Echo Do your homework SLAs are for everyone Achieving the goal Backups To share or not to share Ensuring quality When things go wrong Red Amber Green Increasing resilience Summary 3. Call Routing with Asterisk Routing methods Where to start Internal calls Local calls National calls International calls Alternative options ENUM DUNDi Types of routing Routing techniques Summary 4. Call CentersQueues and Recording Asterisk queues Queue gotchas A practical queue Using queues to cascade calls Call recordingthe issues Show-stoppers VoIP recording approaches Impact of VoIP on recording systems Hardware convergence Distributed call centers Home working VoIP recording challenges Routing Bandwidth Encryption Solutions Asterisk call center solutions How VICIDIAL works Handling inbound calls Installation Timing sources Scalability Summary 5. Asterisk and Speech Technology Why speech-enable? Types of speech technologies Automatic Speech Recognition (ASR) Isolated Word Recognition Connected Word Recognition Natural Language Recognition Text-to-Speech (TTS) Speaker Verification and Identification (SVI) MRCP Implementation considerations ASR and Asterisk Installing LumenVox speech recognition with Asterisk Checking that things are working SpeechCreate() SpeechLoadGrammar (yesno,/etc/lumenvox/Lang/BuiltinGrammars/ABNFBoolean.gram) SpeechActivateGrammar(yesno) SpeechBackground(beep) Verbose(1,Result was ${SPEECH_TEXT(0)}) Verbose(1,Confidence was ${SPEECH_SCORE(0)}) SpeechStart() SpeechDeactivateGrammar(label) SpeechUnloadGrammar(label) SpeechDestroy() ${SPEECH(results)} Grammar files Implementation advice for ASR TTS with Asterisk Implementation advice for TTS Summary 6. Call Accounting and Billing Call Data Records (CDRs) CDR frontends Call accounting Providing termination billing Every little helps Selecting a billing platform Introducing A2Billing Reasons to consider A2Billing A2Billing requirements Monitoring usage Coding for A2Billing Billing gotcha! High call volumes Other high-call-volume solutions SER/OpenSER FreeSWITCH Summary 7. Resilience and Stability Increasing availability Stability Network Cables Switches and routers Endpoints Telephony switches and gateways Server Environment Dealing with failure Network resilience Server High availability Ultra Monkey Telephony switches/gateways Redfone foneBRIDGE2 Junghanns ISDNguard Endpoints Round robin DNS Say hello to Rsync Limiting the number of calls per server Summary 8. Localization and Practical Security Tones Time and date and localization Changing the language of system prompts Local telephony interfaces Analog Digital Localizing caller ID signaling on Digium analog interfaces Checklist Practical security Out of hours Summary 9. Interfacing with Traditional Analog and Digital Telephony Analog Digital ISDN BRI (Basic Rate Interface) ISDN PRI (Primary Rate Interface) Choices, choices Using external adaptors Using cards Installing a Digium card Card installationphysical Installing the DAHDI software Configuring the DAHDI files to enable the card What about the other cards? framing coding Troubleshooting with Digium cards Summary 10. Integrating Asterisk with Wireless Technologies Why integrate Asterisk with wireless technologies? Wireless technology overview Wi-Fi (only) phones SIP desk phones with a wireless link Dual-mode (GSM and SIP) phones and PDA/smart phones SIP/DECT phones Connecting Asterisk to mobile networks Why connect to mobile networks? The GSM gateway (box) The GSM card Configuring wireless devices Configuring Asterisk to work with wireless technologies Deployment choices Neat money saving tricks Calling a mobile phone Avoiding those nasty roaming charges that arise from receiving calls Summary 11. Graphical User Interfaces Reasons for going GUI Good to GUI Ease of administration Access to enhanced features Easier upgrade process Standardized code GUI, phooey! Performance Stability Restricted functions FreePBX How it works Installation Configuration Extensions Inbound routes Outbound routes Trunks Other records Summary A. Selling Your Solution In the beginning ... Drivers for changing phone systems A word on cost Generating interest Alliances Advertising Search engines Become an expert Relationship marketing Email as a marketing tool Tracking prospects Converting the prospect into a sale Determining your customers hardware requirements Choosing the right phones Tales of woe Aastra Linksys Siemens Gigaset IP DECT phones Snom M3 Remote support Make it secure Do's and don'ts The do's First impressions Get brochures printed Take notes Send the quote in a timely manner Follow up the quote Target the decision makers, but don't ignore IT The don'ts You don't need a fancy office Don't cut corners on the solution Don't under price Don't have a huge margin on handsets Don't supply a PC as the phone server Summary B. Sample Email Content What is VoIP? Why should I consider VoIP? Cost savings Call costs Line rental costs Wiring costs Reduced infrastructure costs Centralized management System integration Unified messaging Reliability Closed and open systems Superior sound Fallback solutions Broadcasting calls A number for life Number porting Local numbers About XYZ Our philosophy Our passion C. Sample Appointment Sheet Index