The architecture of today's Internet was mainly designed together with the TCP and IP protocols in the 1970s and early 1980s. During the last years, researchers and funding organisations in America, Europa, Asia have started to work on different alternative architectures for the Internet. Some consider an evolutionnary approach where the Internet architecture would be incrementally modified in a backward compatible manner while other consider that a completely new architecture should be developped to take into account the requirements of today's and tomorrow's Internet.