More and more businesses today have their receive phone service through Internet instead of local phone company lines. Many businesses are also using their internal local and wide-area network infrastructure to replace legacy enterprise telephone networks. This migration to a single network carrying voice and data is called convergence, and it's revolutionizing the world of telecommunications by slashing costs and empowering users. The technology of families driving this convergence is called VoIP, or Voice over IP.
VoIP has advanced Internet-based telephony to a viable solution, piquing the interest of companies small and large. The primary reason for migrating to VoIP is cost, as it equalizes the costs of long distance calls, local calls, and e-mails to fractions of a penny per use. But the real enterprise turn-on is how VoIP empowers businesses to mold and customize telecom and datacom solutions using a single, cohesive networking platform. These business drivers are so compelling that legacy telephony is going the way of the dinosaur, yielding to Voice over IP as the dominant enterprise communications paradigm.
Developed from real-world experience by a senior developer, O'Reilly's
Switching to VoIP provides solutions for the most common VoIP migration challenges. So if you're a network professional who is migrating from a traditional telephony system to a modern, feature-rich network, this book is a must-have. You'll discover the strengths and weaknesses of circuit-switched and packet-switched networks, how VoIP systems impact network infrastructure, as well as solutions for common challenges involved with IP voice migrations. Among the challenges discussed and projects presented:
- building a softPBX
- configuring IP phones
- ensuring quality of service
- scalability
- standards-compliance
- topological considerations
- coordinating a complete system ?switchover?
- migrating applications like voicemail and directory services
- retro-interfacing to traditional telephony
- supporting mobile users
- security and survivability
- dealing with the challenges of NAT
To help you grasp the core principles at work,
Switching to VoIP uses a combination of strategy and hands-on "how-to" that introduce VoIP routers and media gateways, various makes of IP telephone equipment, legacy analog phones, IPTables and Linux firewalls, and the Asterisk open source PBX software by Digium. You'll learn how to build an IP-based or legacy-compatible phone system and voicemail system complete with e-mail integration while becoming familiar with VoIP protocols and devices.
Switching to VoIP remains vendor-neutral and advocates standards, not brands. Some of the standards explored include:
- SIP
- H.323, SCCP, and IAX
- Voice codecs
- 802.3af
- Type of Service, IP precedence, DiffServ, and RSVP
- 802.1a/b/g WLAN
If VoIP has your attention, like so many others, then Switching to VoIP will help you build your own system, install it, and begin making calls. It's the only thing left between you and a modern telecom network.
Customer Reviews & Comments
It seems like Voice over Internet Protocol, aka VoIP, is starting to become much more mainstream. Not only are businesses switching over, but now you can set up your home phone access to use VoIP (aka "broadband") technology. Ted Wallingford has done a nice job in explaining the business side of the possibilities in the book Switching to VoIP - A Solutions Manual for Network Professionals.
Contents: Voice and Data - Two Separate Worlds?; Voice over Data - Many Conversations, One Network; Linux as a PBX; Circuit-Switched Telephony; Enterprise Telephone Applications; Replacing the Voice Circuit with VoIP; Replacing Call Signaling with VoIP; VoIP Readiness; Quality of Service; Security and Monitoring; Troubleshooting Tools; PSTN Trunks; Network Infrastructure for VoIP; Traditional Apps on the Converged Network; What Can Go Wrong?; VoIP Vendors and Services; Asterisk Reference; SIP Methods and Responses; AGI Commands; Asterisk Manager Socket API Syntax; Glossary; Index
I think the biggest thing to keep in mind when approaching this book is the target audience. While there are a few books out there on "internet telephones" that talk to the consumer, this isn't one of them. The tag line of "for Network Professionals" is the key here. While you don't have to be a network guru to read this book, some level of familiarity with network and telephony concepts would help. Someone either working with the communication systems in a company or heading up a communications department would be a perfect match here. You'd probably even do alright if you just have an interest in the subject, as Wellingford does a good job taking what can be complex material and making it understandable. An admirable task in itself...
What makes this book stand out from other books I'd expect to see is that it doesn't just dwell on jargon and theory. There are a number of projects included in the book so you can get your hands dirty actually working with the technology. Add to that the fact that the author uses an open source PBX system called Asterisk for the exercises. So now you have no reason in terms of cost for not diving right in.
Although I'm not necessarily the target audience for this book, I'd have no problem recommending it to someone looking for material that covers this subject. The book is very well written, and after finishing it you should have a very firm grasp of the essentials. You might even know enough to start yourself on your next career path... :)
