| The area of networked group communications is by no means a new field of study. For several years now, researchers and engineers have been studying more efficient ways to harness the potential of Internet protocol (IP)-based networks as the basis for communications in multiparty scenarios. There are many possible approaches to multiparty or group communications, and there are different communications methods and protocols that can be deployed to establish communications within a group. One such method is IP multicast—which takes place at the IP network layer within the transmission control protocol/Internet protocol (TCP/IP) model.
Although there have been several books dedicated to IP multicast and other forms of group communications, none has been dedicated to the topic of security in IP multicast networks and the applications that use them. This book attempts to fill that gap, and provide a snapshot of the current state of the art in the network industry.
In many ways, the area of multicast security is still in its infancy. Although the concept of IP multicast can be traced back to the earlier works of Deering in the late 1980s, serious attention was given to IP multicast—and thus to its security issues—only in the late 1990s. At this time, various players in the industry, notably the content industry, saw the potential of IP multicast as a vehicle for delivering data to vast numbers of users.
Satellite TV distribution, software distribution, stock quote streaming, Web caching, and multimedia conferencing are examples of applications that require one-to-many or many-tomany group communication. Multicast enables efficient group communication by allowing the sender to transmit a single copy of data, with network elements such as routers and switches making copies as necessary for the receivers. Thus multicast reduces the computational load at the sender, as well as the number of copies of data on the network.
Unfortunately, despite the vast amount of research and development of multicast protocols in the past decade, deployment of multicast applications has been slow. While some attribute this to no ‘‘killer applications,’’ the major factor is, in fact, that multicast services lack support for traffic management, accounting and billing, reliability, and security. |
