On network coded filesystem shim: Over-the-top multipath multi-source made easy

Although network coding has shown the potential to revolutionize networking and storage, its deployment has faced a number of challenges. Usual proposals involve two approaches. First, deploying a new protocol (e.g., Multipath Coded TCP), or retrofitting another one (e.g., TCP/NC) to deliver benefits to any application in a computer. However, incorporating new protocols to the Internet is a challenging and slow process. Second, deploying coding at the application layer, which forces each application to implement network coding. This paper proposes an alternative approach through the use of a network coded filesystem shim (NCFSS), where coded data is generated at the filesystem level supporting any application and any network protocol. Our design allows multiple sources of a content to serve data without coordination to a receiver over multiple data paths. Another interesting feature of our approach is that it allows caches in the network to store only a fraction of a specific content in coded form, but sharing the same object identification, i.e., it simplifies the signaling and search of coded content. We describe the NCFSS design and implementation using FUSE and carry out measurements using servers in six countries to demonstrate gains of two to five fold in download speed.