In this talk I will describe some recent work at MSR Cambridge to measure Microsoft’s enterprise network as seen from our site. I will describe our collection method, the problems we faced, and the solutions we implemented. I will describe the data we collected, totalling 13TB of network traffic, to give a flavour of the traffic on our enterprise network in aggregate, per-application and per-host. Finally, I will use OSPF data to outline the topological properties of the network in which our site resides. In summary, we find that there is extreme volatility in application traffic both temporally and spatially (i.e. over time and between hosts); the application mix is significantly different to prior studies of Internet backbone traffic and university campus traffic; and the network is quite stable. This was joint work with Rebecca Isaacs and Dinan Gunawardena, with additional analysis from Laurent Massoulie and Peter Key.