Re-designing Compact-structure based Forwarding for Programmable Networks

Forwarding packets based on networking names is essential for network protocols on different layers, where the ‘names’ could be addresses, packet/flow IDs, and content IDs. For long there have been efforts using dynamic and compact data structures for fast and memory-efficient forwarding. In this work, we identify that the recently developed programmable network paradigm has the potential to further reduce the time/memory complexity of forwarding structures by separating the data plane and control plane. This work presents the new designs of network forwarding structures under the programmable network paradigm, applying three typical dynamic and compact data structures: Bloom filters, Cuckoo hashing, and Othello hashing. We conduct careful analyses and experiments in real networks of these forwarding methods for multiple performance metrics, including lookup throughput, memory footprint, construction time, dynamic updates, and lookup errors. The results give rich insights on designing forwarding algorithms with dynamic and compact data structures. In particular, the new designs based on Cuckoo hashing and Othello hashing show significant advantages over the extensively studied Bloom filter based methods, in all situations discussed in this paper.