Internet protocol (IP) telephony (IPT), or voice over IP (VoIP), has recently changed the telecommunications world, as it allows for transporting voice over IP networks, together with other types of traffic, in an integrated way. IPT offers flexibility, scalability, and cost savings over traditional telephony networks. Although voice is the core application depicted in the technology name, IPT is not strictly limited to it. There are other types of communication that users are accustomed to in traditional telephony: fax, modem, and even text telephony.

Unfortunately, the possibility of deploying these applications within IPT, sharing the same benefits as voice, is often overlooked. Similarly, the necessity to understand how to implement any of these applications over IP networks is rarely addressed in a comprehensive manner. This book represents a unique resource that covers the design, configuration, and troubleshooting of nonvoice communications transport over IP.

The text is divided into four parts. Part 1 starts with the basics of fax, modem, and text telephony. The second part is titled “IP Solutions and Design.” The next part offers the configuration guides, including samples and tips. Part 4, “Troubleshooting,” contains guides that present the essential methodologies for debugging, problem analysis, and resolution. This part is very important due to the number of devices and protocols involved in integrated IP networks that support voice, together with fax, modem, and text applications.

This book is a companion to other IPT resources, as it does not cover the basics of VoIP, such as H.323 or session initiation protocol (SIP) in general; however, all necessary features related to fax, modem, and text communications are covered. The complexity of the area is reflected in the size of the book (600 pages).

The book is written by two Cisco Certified Internetwork Experts (CCIEs) in voice, fax, and modem technologies, who have extensive experience in network design and troubleshooting. Therefore, the text focuses on Cisco equipment and its configuration and troubleshooting. The Cisco IOS voice gateway examples and features target Cisco IOS Software Release 12.4(9)T1; yet, due to the variety of Cisco voice networking products, for any real-life configuration, it is still safer to refer to the up-to-date Cisco documentation online.

I highly recommend this book to IPT administrators, network designers, and voice engineers. The prerequisite is a good understanding of VoIP: control protocols, voice gateways, and quality of service (QoS) issues. Familiarity with Cisco Unified voice products and IOS would also be useful.

One drawback is that the reader is left alone in the IPT abbreviations jungle, as there is no list of abbreviations used throughout the book, and the index is of only limited help. Some abbreviations are not even decoded in the text. Readers may also miss the complete overview of the related standards--namely, International Telegraph and Telephone Consultative Committee (CCITT)/Telecommunication Standardization Sector (ITU-T) recommendations--that form the groundwork for fax and modem communications and text telephony.