Performance evaluation of multicast overlay routing protocols

The multicast communication is one of the fundamental types of the modern network connections. Even though the concept is not new, and exists as a part of the TCP/IP protocol stack, the reality of the backbone networks has been rejecting the technology, mostly due to the economical reasons. On the other hand the development of the basic point to point connections increased the overall Internet capabilities beyond a point, where an application layer implementation of the multicast communication becomes a feasible solution. Even though there exist several practical implementations of the concept, their evaluation seems lacking with the regard to many important aspects. Many comparisons focus on very objective overlay metrics that mostly describe the static properties of the analyzed structures. However muticast group connections tend to be very dynamic, with nodes joining and leaving the transmission session. It is therefore equally important to put stress on the dynamic qualities such as the latency of the overlay´s integrity in the face of a sudden tearing the mutlicast apart due to any of numerous possible causes. The paper focuses on the multicast implementation evaluation, points out some flaws of the current methods of their evaluation and proposes some complementary techniques. As a result a broader view of the problem is provided as a supplement with a greater emphasis on the user point of view.