Towards Slack-Aware Networking

We are moving towards an Internet where most of the packets may be consumed by \emph{machines} -- set-top-boxes or smart-phone apps prefetching content, Internet of Things (IoT) devices uploading their data to the cloud, or data centers doing geo-distributed replication. We observe that such machine centric communication can afford to have \emph{slack} built into it: every packet can be marked as to when it will be consumed in future. Slack could be anywhere from seconds to hours or even days. In this paper, we make a case for slack-aware networking by illustrating slack opportunities that arise for a wide range of applications as they interact with the cloud and its pricing models (e.g., spot pricing). We also sketch the design of SlackStack, a network stack with explicit support for slack at multiple levels of the stack, from a slack-based interface to slack-aware optimizations at the transport and network layers.