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IP Telephony with H.323: Architectures for Unified Networks and Integrated Services
Computer Communications 26 (2003) 1431 www.elsevier.com/locate/comcom
Book Review IP Telephony with H.323: Architectures for Unified Networks and Integrated Services Vineet Kumar, Markku Korpi, Senthil Sengodan; Wiley, New York, 2001, 605 pages, ISBN 0471393436 (US$ 65.00) IP telephony has proved to be one of the promising modern applications over IP networks. Telephony realized over IP networks may significantly save the communications costs and at the same time leads to an integrated services network. The common standardized solution to IP telephony is based on the ITU-T recommendation H.323 that went through several versions. In fact, the H.323 relates to several other indispensable protocols specified in other ITU-T documents, namely H series (multimedia systems) and G series (coders). Although most of the recommendations are not brand new, they are highly complex and not commonly well understood within the IP community, mainly network designers and advanced users. The communication standards, ITU-T recommendation inclusive, are usually difficult to “read” and to easily comprehend (not speaking about the cost of the actual documents that are unfortunately still mostly unavailable for free). Besides, IP telephony is indeed a complex technology. Therefore it is very recommendable to read a companion book where the concepts and related issues are thoroughly explained by those participating in the standards development. That is the case for the IP Telephony with H.323 book. Apart from ITUT-defined protocols the book also introduces the Internet protocols related to real-time delay-sensitive traffic, such as RTP/RTCP (Real-time Transport Protocol/Real-Time Control Protocol) and SDP (Session Description Protocol). The publication is not for beginners but rather for those who have strong background in networking and telecommunications. It is aimed at those wishing to gain not only superficial understanding of IP telephony but at those with a need for a detailed knowledge of the technology and its cornerstones. Hence, telephony implementers whether coming from datacom or telecom world, belong to the primary category of readers. The networking professionals and advanced students, who plan to work in this area with a high demand of specialists, will also benefit from the book.
The book provides a right balance between the theory behind the modern technology (protocols’ internals) and the actual implementation issues of IP telephony. The implementers often lack the complete picture but having studied this book will definitely help them gain the complete understanding and appreciation for the technology. The book consists of 17 chapters, a glossary, an acronym list, and an index. Each chapter is accompanied by its own list of references and recommended reading. Additionally, at the end of each chapter the diligent reader may find several problems that test his understanding of the covered topics. The book starts with the basic topics such as the signaling, control, and media protocols to initiate, communicate, and terminate a call, and call routing and mechanism for timing the length of the call. It also describes how to enable the conference calls to allow hundreds and thousands of participants communicate in real-time. Supplementary services are described in detail. The book also provides an insight into more advanced topics such as QoS and mobility in IP telephony systems. Indispensable to the IP telephony discussion are details of security features provided by TCP/IP stack (IPsec) and within H.235 and H.323 for user authentication, securing the three signaling channels, and providing confidentiality for the media stream. Readers will also learn how to use HTTP protocol to control telephone calls via a web interface. Additionally, deployment scenarios of various types of gateways including network access gateways, trunking gateways, and residential gateways are brought to readers’ attention. To summarize, the IP Telephony with H.323 book is recommendable for advanced readers as a comprehensive reference covering the protocol family enabling the telephony (multimedia) service over IP networks.
0140-3664/03/$ - see front matter q 2003 Elsevier Science B.V. All rights reserved. doi:10.1016/S0140-3664(03)00039-2
Rita Puzmanova, PhD, MBA Independent networking Specialist trainee and writer, Czech Republic Accepted 20 January 2003
Book Review IP Telephony with H.323: Architectures for Unified Networks and Integrated Services Vineet Kumar, Markku Korpi, Senthil Sengodan; Wiley, New York, 2001, 605 pages, ISBN 0471393436 (US$ 65.00) IP telephony has proved to be one of the promising modern applications over IP networks. Telephony realized over IP networks may significantly save the communications costs and at the same time leads to an integrated services network. The common standardized solution to IP telephony is based on the ITU-T recommendation H.323 that went through several versions. In fact, the H.323 relates to several other indispensable protocols specified in other ITU-T documents, namely H series (multimedia systems) and G series (coders). Although most of the recommendations are not brand new, they are highly complex and not commonly well understood within the IP community, mainly network designers and advanced users. The communication standards, ITU-T recommendation inclusive, are usually difficult to “read” and to easily comprehend (not speaking about the cost of the actual documents that are unfortunately still mostly unavailable for free). Besides, IP telephony is indeed a complex technology. Therefore it is very recommendable to read a companion book where the concepts and related issues are thoroughly explained by those participating in the standards development. That is the case for the IP Telephony with H.323 book. Apart from ITUT-defined protocols the book also introduces the Internet protocols related to real-time delay-sensitive traffic, such as RTP/RTCP (Real-time Transport Protocol/Real-Time Control Protocol) and SDP (Session Description Protocol). The publication is not for beginners but rather for those who have strong background in networking and telecommunications. It is aimed at those wishing to gain not only superficial understanding of IP telephony but at those with a need for a detailed knowledge of the technology and its cornerstones. Hence, telephony implementers whether coming from datacom or telecom world, belong to the primary category of readers. The networking professionals and advanced students, who plan to work in this area with a high demand of specialists, will also benefit from the book.
The book provides a right balance between the theory behind the modern technology (protocols’ internals) and the actual implementation issues of IP telephony. The implementers often lack the complete picture but having studied this book will definitely help them gain the complete understanding and appreciation for the technology. The book consists of 17 chapters, a glossary, an acronym list, and an index. Each chapter is accompanied by its own list of references and recommended reading. Additionally, at the end of each chapter the diligent reader may find several problems that test his understanding of the covered topics. The book starts with the basic topics such as the signaling, control, and media protocols to initiate, communicate, and terminate a call, and call routing and mechanism for timing the length of the call. It also describes how to enable the conference calls to allow hundreds and thousands of participants communicate in real-time. Supplementary services are described in detail. The book also provides an insight into more advanced topics such as QoS and mobility in IP telephony systems. Indispensable to the IP telephony discussion are details of security features provided by TCP/IP stack (IPsec) and within H.235 and H.323 for user authentication, securing the three signaling channels, and providing confidentiality for the media stream. Readers will also learn how to use HTTP protocol to control telephone calls via a web interface. Additionally, deployment scenarios of various types of gateways including network access gateways, trunking gateways, and residential gateways are brought to readers’ attention. To summarize, the IP Telephony with H.323 book is recommendable for advanced readers as a comprehensive reference covering the protocol family enabling the telephony (multimedia) service over IP networks.
0140-3664/03/$ - see front matter q 2003 Elsevier Science B.V. All rights reserved. doi:10.1016/S0140-3664(03)00039-2
Rita Puzmanova, PhD, MBA Independent networking Specialist trainee and writer, Czech Republic Accepted 20 January 2003