VirtualStack: Adaptive Multipath Support through Protocol Stack Virtualization.

More and more network devices, such as servers or smartphones, have multiple network interfaces. Today's commonly used communication protocols do not leverage these interfaces to increase bandwidth and reliability using multiple network paths. Recent approaches, such as Multipath TCP (MPTCP), clearly show these advantages. However, adaptation of MPTCP is slow as it requires a modified kernel and faces compatibility issues inside the network. MPTCP is also inflexible in the sense that all paths must use TCP. The challenge is to support multipathing on any operating system, with any legacy application using any transport layer protocol. In this paper, we present VirtualStack. VirtualStack manages multiple network stacks per application and decides on the best stack on a per-packet basis. This allows to support multipath using any combination of interfaces and protocols for every application. We evaluate the multipath support by comparing VirtualStack against MPTCP using a combination of TCP and UDP connections. Additionally, we show how rules provide flexible programmings abstractions for VirtualStack.