October 13, 2005
Hot Off the O'Reilly Press: Switching to VoIP
Voice over IP has been around for years, and many were wondering when it would grow up. It just did. VoIP slammed through adolescence over the last year or so and is now a "newly mature" technology with many benefits and rapidly dropping deployment costs. But if you're new to the technology, it can be hard to get your arms around. That's where O'Reilly's new book "Switching to VoIP" fills a void. This gem of a techno primer by Theodore Wallingford explains VoIP better than any other book I've seen to date.
The book starts out with an essential introduction to the differences between legacy business phone systems, such as Key systems and PBXs, and VoIP switching. If you aren't familiar with such terms as POTS, trunk, T1, TDM, Dial Plan, ACH, and the like, Wallingford's first five chapters will give you a thorough grounding in telco talk. He also introduces the idea of running a Linux computer as an enterprise PBX, which will be shocking to some, but turns out to be very doable using the open-source VoIP software called Asterisk.
The book then dives into the details of VoIP signaling and transport, various sound encoding algorithms, and a checklist of issues you should address before rolling out a new VoIP implementation. For example, are your users ready to accept a major paradigm shift in their voice communications? Is your network beefy enough to accommodate the increased traffic of VoIP, and can you give VoIP packets the priority they need to maintain call quality and reliability? Do you have special security or regulatory compliance needs?
All these factors affect the cost and time to deploy VoIP. Wallingford helps you make a business case for (or against) VoIP, and if VoIP is in your future, explains how to construct a competent implementation plan, including vendor RFPs for equipment and software acquisition.
Once you begin rolling out a VoIP system, you'll encounter technical problems. Wallingford addresses these with seven chapters on operational topics: QoS, security and monitoring, troubleshooting tools, PSTN trunk issues, network infrastructure, legacy applications, and common problems. These chapters concentrate valuable old-hand VoIP deployment experience that you'd have to spend years accumulating on your own.
The book ends with chapters summarizing VoIP vendors and services, and the Asterisk open-source product. Three appendices provide handy references to SIP transactions, AGI commands, and Asterisk management APIs.
If you're seriously considering VoIP in your enterprise, this is the go-to book. It's available both in print and through O'Reilly's excellent Safari online book reading service.
Posted by Mel Beckman at October 13, 2005 8:47 AM
