VoIP For Dummies (For Dummies (Computer/Tech))
By timothy v. kelly
Comments
A book on general VoIP
(2006-08-13)
This book is a non-technical book on VoIP that explains to the reader what VoIP is and why companies and individuals can benefit from it. It talks about cost saving using VoIP. In my opinion there are 2 benefits from VoIP: cost saving and (extra data-voice) features. The author could have written a bit more about (extra possible convergence) features. If you want a technical book for implementing VoIP, there are others more suited to your needs. The gateway part discussed in another review can be found (theoretically, not practically) in Voice over the packet network from Wright. Mr. Kelly's book was to the point, concise and comprehensable. An excellent primer. The review using a lot of abbreviations and technical terms was not to the point, since it just sums some terms whose meaning can be looked up on for instance wikipedia. The basic function of these terms is discussed in general in this book. (The reviewer sums a lot of Voice codecs for instance.)
Good Introductory Book
(2006-08-13)
The basic technology of the conventional telephone system has been around since the very beginning. You make a call and you get a dedicated communications channel to the instrument at the other end. And in the beginning that was indeed a physical wire. This wiring circuit was physically switched to your phone and stayed there until you hung up. Later Bell Labs was set up to discover how to get more signals through a wire than just one message at a time. Everyone knew that you could get more signal through a wire than just one phone call. And running all that wire was expensive, especially when it ran underwater across the Atlantic.
Step forward a few decades. The internet isn't circuit switched like this. Instead it's packet switched. A packet of data has it's own address as to where it's supposed to go and is thrown up on the network. It makes its way to the intended receiver. That's the way this message got to you. Suppose instead that that packet was a little tidbit of digitized voice. With the proper instrument on the receiving end (let's call it a telephone) the data is converted back into voice.
That's what VOIP is all about. To learn the details, buy this book. It's a complete description of what it's all about from equipment, procedures, and a bit of the background technology.
Only one last comment -- keep at least one regular, old fashioned, hard wired (not cordless) telephone around. If you have a fire, that knocks the power out, you want something that will let you call 911. Note that the authors say the same thing on pages 44 & 225.
Well, one more last thing. The cost savings on VOIP are difficult to estimate. SBC just came around here and offered 500 minutes a month of nationwide long distance for $10 a month. But if Grandma or the Grandkids live overseas, the cost savings are great. The book talks about this on page 50.
VERY High Level Stuff
(2006-08-13)
This book isn't for technical people looking to implement a VoIP solution. It doesn't even define the terms one typically finds in eBay auction descriptions. For example, a typical description for a VoIP phone contains statements like:
- Support popular vocoders including G.723.1 (5.3K/6.3K), G.729A/B, G.711 (a-law and u-law), G.726, G.728, and wide-band G.722 (Model 102D).
- Support Silence Suppression, VAD (Voice Activity Detection), CNG (Comfort Noise Generation), Line Echo Cancellation (G.168), and AGC (Automatic Gain Control)
There is no introduction to this terminology in the book. Only a few paragraphs on SIP and nothing on H.323, SCCP, or IAX. Nothing about setting up gateways or servers. No mention of Asterisk or Digium cards or Skype.
According to the back cover the author is a business professor which is likely the reason for the lack of technical material. I get the impression he is well-versed in traditional telephony systems but his actual hands-on experience with VoIP systems is very limited if it exists at all.
(2006-08-13)
This book is a non-technical book on VoIP that explains to the reader what VoIP is and why companies and individuals can benefit from it. It talks about cost saving using VoIP. In my opinion there are 2 benefits from VoIP: cost saving and (extra data-voice) features. The author could have written a bit more about (extra possible convergence) features. If you want a technical book for implementing VoIP, there are others more suited to your needs. The gateway part discussed in another review can be found (theoretically, not practically) in Voice over the packet network from Wright. Mr. Kelly's book was to the point, concise and comprehensable. An excellent primer. The review using a lot of abbreviations and technical terms was not to the point, since it just sums some terms whose meaning can be looked up on for instance wikipedia. The basic function of these terms is discussed in general in this book. (The reviewer sums a lot of Voice codecs for instance.)
Good Introductory Book
(2006-08-13)
The basic technology of the conventional telephone system has been around since the very beginning. You make a call and you get a dedicated communications channel to the instrument at the other end. And in the beginning that was indeed a physical wire. This wiring circuit was physically switched to your phone and stayed there until you hung up. Later Bell Labs was set up to discover how to get more signals through a wire than just one message at a time. Everyone knew that you could get more signal through a wire than just one phone call. And running all that wire was expensive, especially when it ran underwater across the Atlantic.
Step forward a few decades. The internet isn't circuit switched like this. Instead it's packet switched. A packet of data has it's own address as to where it's supposed to go and is thrown up on the network. It makes its way to the intended receiver. That's the way this message got to you. Suppose instead that that packet was a little tidbit of digitized voice. With the proper instrument on the receiving end (let's call it a telephone) the data is converted back into voice.
That's what VOIP is all about. To learn the details, buy this book. It's a complete description of what it's all about from equipment, procedures, and a bit of the background technology.
Only one last comment -- keep at least one regular, old fashioned, hard wired (not cordless) telephone around. If you have a fire, that knocks the power out, you want something that will let you call 911. Note that the authors say the same thing on pages 44 & 225.
Well, one more last thing. The cost savings on VOIP are difficult to estimate. SBC just came around here and offered 500 minutes a month of nationwide long distance for $10 a month. But if Grandma or the Grandkids live overseas, the cost savings are great. The book talks about this on page 50.
VERY High Level Stuff
(2006-08-13)
This book isn't for technical people looking to implement a VoIP solution. It doesn't even define the terms one typically finds in eBay auction descriptions. For example, a typical description for a VoIP phone contains statements like:
- Support popular vocoders including G.723.1 (5.3K/6.3K), G.729A/B, G.711 (a-law and u-law), G.726, G.728, and wide-band G.722 (Model 102D).
- Support Silence Suppression, VAD (Voice Activity Detection), CNG (Comfort Noise Generation), Line Echo Cancellation (G.168), and AGC (Automatic Gain Control)
There is no introduction to this terminology in the book. Only a few paragraphs on SIP and nothing on H.323, SCCP, or IAX. Nothing about setting up gateways or servers. No mention of Asterisk or Digium cards or Skype.
According to the back cover the author is a business professor which is likely the reason for the lack of technical material. I get the impression he is well-versed in traditional telephony systems but his actual hands-on experience with VoIP systems is very limited if it exists at all.