Networking researchers have been using tools like wireshark and tcpdump to sniff packets on physical links that use different types of datalink protocols, e.g. Ethernet or 802.11, allowing them to monitor higher level protocols sharing these links. However, monitoring wireless links is more challenging, since the transmission medium is shared by flows using diverse datalink protocols (e.g. 802.11, Bluetooth) and physical layer schemes (e.g. QPSK and GFSK). To this end, we propose RFDump, a software architecture for monitoring packets on heterogeneous wireless networks. The key idea underlying our architecture is the use of a fast detection stage which can tentatively map signals to protocols very efficiently. As a result, RFDump can scale up to a modest number (5-10) of wireless technologies.

The Border Gateway Protocol (BGP) allows each autonomous system (AS) to select routes to destinations based on semantically rich and locally determined policies. This autonomously exercised policy freedom can cause instability, where unresolvable policy-based disputes in the network result in interdomain route oscillations. Several recent works have established that such instabilities can only be eliminated by enforcing a globally accepted preference ordering on routes (such as shortest path). To resolve this conflict between policy autonomy and system stability, we propose a distributed mechanism that enforces a preference ordering only when disputes resulting in oscillations exist. This preserves policy freedom when possible, and imposes stability when required.