Book Image

Asterisk 1.4 - the Professional's Guide

Book Image

Asterisk 1.4 - the Professional's Guide

Overview of this book

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.
Table of Contents (20 chapters)
Asterisk 1.4
Credits
Foreword
About the Authors
About the Reviewers
Preface
9
Interfacing with Traditional Analog and Digital Telephony
Sample Appointment Sheet

Why should I consider VoIP?


VoIP is considered to be futuristic technology, more so than the mobile revolution was back in the eighties. Why? Because it's set to completely change the way you think about your telephone calls. No longer are you constrained about what your local telephone exchange can do—you can make the phones work the way you run your business, and not make your business run around how the phones work.

It's all about convergence. No longer should you consider your phone and data traffic separate. Now they can interoperate with one another. It is now perfectly possible to prioritize calls coming into a company based on information that the company holds about the caller.

Ultimately, moving to VoIP is not just about cost savings, but having the ability to significantly improve the way you run your business.

Cost savings

The payback time on a VoIP system could be a matter of months depending upon the system employed. With a traditional phone system, there is no payback! How is this achieved?

Call costs

Many destinations around the world are 1p/min and significant cost savings are to be made to mobiles. However, it is our belief that this saving, while great, will be short term. Before long, paying for a phone call will be as alien as paying for email.

Line rental costs

Here, significant ongoing costs savings can be made. Given that even today a single broadband line can support up to eight calls with full PSTN quality, or fifteen calls using the compressed GSM codec, many fixed line rentals become redundant.

Wiring costs

Because VoIP runs on CAT5 network cabling, separate phone cabling is not required. In addition, if a phone is required in a new location, moving it is simply a case of unplugging it and taking it to the new location. You won't need a telecoms engineer to run a new cable and reprogram the phone system.

Reduced infrastructure costs

VoIP is not location specific, therefore remote satellite offices can be part of a central telephone system. In smaller branches, a local phone system is not required, as they simply become a remote extension of the main site. Remote/home workers simply need an IP telephone, and using their broadband connection, they become part of the same system with completely free "internal" calls, even if calls are made to the other side of the world.

Centralized management

If you're reducing costs, it doesn't mean that you have to give anything up. In fact, you gain in many significant ways. Just as you can control your data network from your servers, now you can do the same with your voice network.

High granularity reporting and analysis of system usage is now yours in real-time. This means you can see traffic patterns, abuse, and employee performance at a glance.

System integration

Once the preserve of companies with deep pockets, many VoIP systems run using open standards, which means you can efficiently integrate the system with many business applications and databases. Such uses could include the ability to:

  • Pop up customer details before you answer a call

  • Click to dial from the desktop

  • Record calls

  • Store contact lists in company directories accessible from the phone

Unified messaging

This holy grail for the major telcos that was never successfully achieved, is now possible at the company level. Email, voicemail, fax, and presence can now be accessed from one location.

Reliability

In the year 2006, for the first time, VoIP systems outsold traditional phone systems. It is highly unlikely that this would be the case if there were concerns about reliability, and let's face it, BT are spending some eight billion pounds converting their exchanges to IP. Reports of poor quality are invariably down to improperly configured and specified systems.

Closed and open systems

VoIP is relatively new, in the sense that it's been around for approximately ten years. As ever, there were many competing standards, and one primarily open standard—SIP (Session Initiation Protocol). The last eighteen months (at the time of writing) have seen many companies moving over to SIP and abandoning their proprietary protocols. As a result, there has been an explosion in the number of high-quality handsets available.

Superior sound

Traditional phones are restricted to a given bandwidth, and apart from greater clarity, this bandwidth hasn't changed for a hundred years. On the other hand, VoIP is able to take advantage of the advances in digital processing and wideband codecs are now available, which are the equivalent of HD voice.

Fallback solutions

With a traditional system, if builders inadvertently dig up the phone lines outside your office, you could be without phones for days. With a VoIP system, your connection can be monitored 24/7 automatically. In the event that communications fail, a prearranged fallback solution may be engaged. This could range from broadcasting all calls to predefined mobile numbers and/or alternative fixed line numbers, or diverting calls to another office. All of this can happen within seconds with no manual intervention.

Broadcasting calls

A unique feature of VoIP is the ability to broadcast calls. This means that any inbound call can be sent to multiple destinations (for example, office extension and mobile/cell phone) at the "same" time.

A number for life

We're all used to keeping our mobile number even if we change mobile operators, but with fixed line numbers, move the location of the office half a mile from where you are now, and in all probability, you would have to get new numbers because your new location happens to be served by a different exchange.

Number porting

Most telephone numbers can now be ported to IP. This means that even if you relocate to another part of the country, you take your numbers with you!

Local numbers

Recent surveys show that most customers prefer to deal with local companies, and some even refuse to answer out of area calls. With 90% of all area codes in the UK now available for VoIP number allocation, you can present a local number even if you're not physically located in that area.