The Internet is a very large scale complex system whose properties are not entirely completely known. However, a detailed knowledge of the Internet is key to understand the mechanisms and protocols that work well and those that could be improved.

We participate in various measurement activities to better understand the key characteristics of the Internet. Such activities include :

• active measurements where we install probes on nodes to perform delay, bandwidth or traceroute-like measurements
• passive measurements where we analyse raw packet traces or Netflow data to better understand the charactistics of Internet traffic
• routing measurements where we analyse the behaviour of routing protocols such as BGP or OSPF/ISIS in large networks