Thursday, March 12, 2009

VoIP Hacks: Tips & Tools for Internet Telephony

VoIP Hacks: Tips & Tools for Internet TelephonyVoice over Internet Protocol (VoIP) is gaining a lot of attention these days, as more companies and individuals switch from standard telephone service to phone service via the Internet. The reason is simple: A single network to carry voice and data is easier to scale, maintain, and administer. As an added bonus, it's also cheaper, because VoIP is free of the endless government regulations and tariffs imposed upon phone companies.

VoIP is simply overflowing with hack potential, and VoIP Hacks is the practical guide from O'Reilly that presents these possibilities to you. It provides dozens of hands-on projects for building a VoIP network, showing you how to tweak and customize a multitude of exciting things to get the job done. Along the way, you'll also learn which standards and practices work best for your particular environment. Among the quick and clever solutions showcased in the book are those for:

  • gauging VoIP readiness on an enterprise network
  • using SIP, H.323, and other signaling specifications
  • providing low-layer security in a VoIP environment
  • employing IP hardphones, analog telephone adapters, and softPBX servers
  • dealing with and avoiding the most common VoIP deployment mistakes

In reality, VoIP Hacks contains only a small subset of VoIP knowledge-enough to serve as an introduction to the world of VoIP and teach you how to use it to save money, be more productive, or just impress your friends. If you love to tinker and optimize, this is the one technology, and the one book, you must investigate.

Customer Review: Nothing Short of Genius

I've been in telephony and networking for nearly 30 years. Started in R&D at a PBX manufacturer in 1979, then did a stretch with the, at that time, worlds largest Ethernet company. Then I worked on a Fiber Optic Voice and Data MAN (IEEE 802.6) and have been manufacturing telecom products for the past 14 years. I think that gives me the qualifications to critique this book even without having to mention the Ethernet board I designed for IBM was featured on the cover of PC Week Magazine in 1987.

This is a very good book. If you are a VoIP systems integrator or do anything with Asterisk, this book is a must have. There are major problems with the current state of the VoIP industry. The two biggest problems are security and the unavailability of a decent broadband connection with QoS and an SLA below $400 per MegaBit. Yes $400, but we're talking guaranteed availability and less than 0.5% packet loss,and 50mS or less latency with real penalties for not meeting the SLA.

Before reading this book I would not have considered putting an IP-PBX on an ADSL link. The author's idea of putting a Sangoma ADLS modem in the Linux box with PPPoE client software and controlling the modem queue is nothing short of genius. Then to top it off with the AstShape QoS scripts and the QoS monitoring tools, this book is an absolute bargain. With these tools I'll not only know if the ADSL connection is capable of supporting VoIP service, but I'll know exactly why. Much better than cutting over to the VoIP system and later discovering the problems. The whole book is just full of great ideas. There is something in this book for everybody from the Skype user to a single VoIP phone owner, Asterisk, or enterprise PBX administrators. Just check out the Table of Contents. Amazon does not have the Table of Contents available but it is on the O'Reilly website oreilly D0T C0M.

While the book is an asset for seasoned VoIP integrators, it is also a very good resource for someone completely unfamiliar with VoIP with a desire to learn. You can start out with free software for a Windows PC, progress to purchasing a single VoIP phone, then to a Linux PC. If you are leary of Linux, either get over it or you should probably stay out of VoIP altogether.

Customer Review: VOIP : for the serious home user or enterprise deployment

Voice over IP, as with most emerging technologies, in the process of shaking up the world, in this case Public Switched Telephone Network and Plain Old Telephony Service. The author starts of the book off at the most basic entry point for most consumers into the world of VoIP, which is background about the main commerical carriers such as Vonage. The introductary chapters continue to build on the most elementary approach, giving the reader advice on modifying the soft phone[s] that the respective carriers will allow or provide to the consumers, such as alternating ring tones. It isn't long before Ted is explaining how to compeletly re-wire the house over to a pure VoIP infastructure using the existing wiring in your home as well as an, or the ATA provided by the carrier. While this is undoubtly over the casual readers head and possibly comfort level it is good see that this option is explored and explained for those that might not be aware of this solution.

Of course, other VoIP solutions are explored. Skype, is mentioned and basic features are explored, although the detail provided on Skype is not as detailed as those of other solutions, which maybe due to the coverage for Skype under the Skype Hacks book. However, the coverage for building your own VoIP via Asterisk is quite detailed and in-depth. Options that explored for this approach, are call forwarding, hold music, voice mail applications and distinctive ring as well as basic advice on setting up and compiling the application. The process appears to be able to easy to implement, but alas was not tried due to this reviewers use of Skype for his VoIP needs.

Also in the closing chapters of the book, issues of improving QoS are addressed as is the legacy signalling protocol that H.323 is since the adoption of SIP. Since QoS is vital to ensuring that VoIP traffic receives the bandwidth that it needs Ted gives us some basic commands to find out if there is jitter [dropped datagrams] and some ways to fix this issue. However, it should be noted that this chapter, as with most of the later half of the book is more in line for larger scale operations that use Linux/Unix and building their own office VoIP solutions.

To summarize, VoIP hacks does offer something for everyone, although the hacks provided in the latter chapters are geared to the enterprise level deployment of VoIP. That's not to say that the information is not relevant or even eye opening, just the average home user will find little to apply this to.
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