Section 1.4. VoIP in the Home

1.4. VoIP in the Home

A number of companies offer VoIP calling services that can be used in the home, more or less replacing conventional PSTN service. They deliver telephone calling capabilities using a broadband Internet connection. Not all of them permit placing calls to or receiving calls from the PSTN, but almost all allow you to call other users of the same service using the Internet instead of the PSTN. Some providers even have "peering" arrangements that allow you to call subscribers to other providers' services using the Internet.

Some of these services work only with proprietary telephone-calling software and don't allow you to use a hardphone. Certain providers can support the use of a special hardphone that connects to your PC's USB port and uses the PC as a gateway mechanism for accessing the network. Others provide an ATA device so that you can use one or more analog phones to place and receive calls using the service. Still others offer the ability to use IP phones.

Many of these services offer competitive calling rates, decent sound quality, and features that are close to that of the traditional phone company. There are solutions for adding more features and interesting hacks to a home-based VoIP network, too. Some of them are covered in this book.

1.5. VoIP in Business

Many vendors are producing cost-effective VoIP server devices for small Ethernet LANs. These devices connect together endpoints in a small office like a PBX, either through the use of conventional analog and digital phones (more on this later) or new-generation IP phones. In either case, connecting calls to the PSTN and between local phones is usually the responsibility of these server deviceslike a PBX or KTSand there are several ways to make that PSTN connection.

Using VoIP in small business environments is easier when there's some network savvy around the office. Some traditional phone vendors are now implementing VoIP systems, so the availability of third-party networking expertise is accelerating the adoption of VoIP in small businesses.

1.6. VoIP's Changing Reputation

There are potential pitfalls along the path to Voice over IP. Implementing VoIP is like any infrastructural investmentit has hard costs and implications for the enterprise user community. How you deal with these costs and social issues is largely defined by how much VoIP you implement at a time. That's why the concept of migrating is important.

Challenges also arise from using a relatively young technology for a task that has been reliably delivered "the old way" for decades. If the data network hosting the VoIP system isn't provisioned correctly, the results can be disastrous. Security, stability, and call quality in a VoIP system are all tied to their counterparts on the underlying data network. If your network is insecure , unstable, or lossy, your IP-based voice system will be, too.

A leading cause of failed VoIP implementations is poor perceived call quality, which usually stems from administrator misunderstanding of VoIP's requirements. VoIP is more than just call management and voice conversations; it is also a comprehensive set of methods to deal with quality of service. Lack of attention to these aspects of VoIP will doom even the most well-intentioned implementer.

These issues have contributed to IP telephony's reputation as difficult to manage, inferior in quality, and even damaging to corporate image. These perceptions can be avoided, and the opposite outcomes achieved, if VoIP is done right.

This book will help you implement and understand VoIP networking, call management, telephony features, and call accounting within the context of an enterprise data network. Along the way, you'll build a useful, real-world call-management system, a voice mail server, and more. You'll employ next -generation VoIP hardware and software, use open source telephony tools, and leverage traditional telephony components . You'll even be able to use that old residential-style analog phone for VoIP calls across the Internet.

You'll understand the differences between old-school and next-generation telephony and be able to implement a software-based PBX, maximize quality of service, and know many of the standards that govern the world of converged networks. You'll be able to identify situations in which traditional telephony can be integrated with IP telephony, and you'll learn how to provision emergency calling services that have always relied on the public telephone system. This way, your switch to VoIP will be a success.