| As more large content/cloud and service providers are making colocation facilities that house an Internet eXchange Point (IXP) their location-of-choice for interconnecting with one another in an effort to shrink the physical as well as network distances between where content resides and where it is consumed, the providers of these facilities and/or the operators of the co-located IXPs are reacting by constantly innovating and expanding their interconnection service offerings. These developments directly impact the long-standing public vs private peering debate, and performing a rigorous measurement study that provides a solid understanding of the actual rather than the perceived cost-performance tradeoffs between the different interconnection service offerings that are available to networks in today's Internet in one and the same colocation facility would go a long way towards putting this debate on scientifically solid foundations. In particular, we argue that an important first step towards achieving this goal is to establish a proven set of measurement methods and techniques to infer both the existence and type of the different interconnections that the networks in a colocation facility with an IXP presence have established with one another. In fact, any realistic assessment of applicationlevel performance and user-perceived quality-of-experience of the traffic that is routed through such a facility will rely critically on our ability to infer the existence and usage of the established interconnections in that facility. |