Network verification, which is mainly about checking network states against network invariants or operator beliefs, has been a popular research thesis recently. Fast calculation of all-pair reachability of the network beforehand for further query or overall analysis can be a huge assistance to network verification. In this paper, we propose a new fast all-pair reachability calculation algorithm Atomic Predicates Flooding(APF). Experiments on real-life datasets show that the new algorithm based on network atomization is about three to four orders of magnitude faster than existing algorithms without network atomization. On most kinds of datasets, APF is even 2 to 5 times faster than the Warshall based all pair reachability algorithm with atomization. We believe that our method is essential for developing more practical and more efficient network and verification tools.

Rate limiting is a fundamental function for managing quality of network service. Unfortunately, the poor scalability of today's rate limiting approaches restricts the performance on multi-core platform. In this work, we present CORAL, a lock-free framework that effectively implements high performance rate limiting on multi-core platform. The key idea is that CORAL uses virtual class queues to isolate simultaneous access to the same queue by different CPU cores and two additional parameters to synchronize the QoS constraints among multi cores. Experimental results show that this lock-free design obtains around 50% higher limiting rate compared to existing locking method, and shows great scalability and stable performance over different number of cores and packet sizes.