Protocol Labs Research
2021-01-14 / Report
Accelerating content routing with Bitswap: A multi-path file transfer protocol in IPFS and Filecoin


Bitswap is a Block Exchange protocol designed for P2P Content Addressable Networks. It leverages merkle-linked graphs in order to parallelize retrieval and verify content integrity. Bitswap is being used in the InterPlanetary File System architecture as the main content exchange protocol, as well as in the Filecoin network as part of the block synchronisation protocol. In this work, we present Bitswap’s baseline design and then apply several new extensions with the goal of improving Bitswap’s efficiency and efficacy and minimizing its bandwidth fingerprint. Most importantly, our extensions result in a substantial increase to the protocol’s content discovery rate. This is achieved by using the wealth of information that the protocol acquires from the content routing subsystem to make smarter decisions on where to fetch the content from.