Towards an Observatory for Network Transparency Research

The Internet is full of Middleboxes that change packets and flows. In fact, there is probably no IP o TCP header that is not affected by at least one middlebox. Obviously, middleboxes impede path transparency, i.e., the idea that an exchange of messages results in more or less the same packets, no matter what path the packets take. But no one seems to have a truly global view of what middleboxes do to packets on what Internet paths, which would however be essential knowledge for new transport protocols to be successfully deployed. We address these concerns in the MAMI project by building an observatory of path transparency measurements. The project hosts an extensive set of path transparency measure\-ments---we believe it to be the first dataset to deal specifically with middlebox involvement. In this paper, we describe that Observatory and a number of questions that we want to address with the data in that Observatory. Eventually, the project will provide public access to that Observatory so that researchers and the interested public can ask their own questions about path transparency issues and middlebox involvement.