IP Network Monitoring and Measurements: Techniques and Experiences (Tutorial)

Abstract

The Internet tends to become the universal network for transmitting all kinds of information, from simple computer data to voice, video, and many interactive real-time information. There is then a strong need for the Internet to provide new kinds of services suited to the requirements of all the Internet applications and all the data they transmit. In addition, the Internet is growing rapidly in size (number of users, computers connected, etc.) as well as in complexity, in particular because of the need to provide new services, and to optimize the use of communication resources to improve the Quality of Service (QoS) provided to users. Because of the Internet complexity increase, the evolution of this global network is tied to an accurate knowledge and understanding of network traffic. Consequently, the development of tools and techniques to capture Internet traffic and its characteristics is now a research and engineering topic of first importance. This tutorial then addresses several techniques for monitoring, measuring and analyzing Internet traffic. In the first part of this tutorial, we will provide a survey of existing approaches and techniques for IP monitoring, in particular dealing with active and passive measurements. This state of the art on IP monitoring and measurements includes the description of basic tools (ping, traceroute, etc...) as well as more advanced devices as OCx-MON, IPANEMA, etc. It also provides a survey on pioneering projects in the domain of IP network monitoring. In the second part of the tutorial, we will show on some actual examples from operational networks how measurements can help in the design, engineering, management of IP networks, as well as in designing new protocols and architectures for next generation Internet, especially addressing the issues of QoS and scalability in large scale IP networks. The following topics will be addressed: Traffic characterization; Traffic modeling; Congestion analysis; Delays in routers; Traffic matrices; Routing table explosion; Summary on QoS. Finally, the tutorial will finish by giving the main issues - not well known - that have to be solved in the Internet, and some research directions to achieve them.