The Internet of Tomorrow Must Sleep More and Grow Old

Today, the ICT industry has a massive carbon footprint (a few percent of worldwide emissions) and one of the fastest growth rates. The Internet accounts for a large part of that footprint while being also energy inefficient; i.e. , the total energy cost per byte transmitted is very high. Thankfully, there are many ways to improve the current status; we discuss two relatively unexplored directions in this paper. Putting network devices to "sleep," i.e. , turning them off, is known to be an efficient vector to save energy; we argue that harvesting this potential requires new routing protocols, better suited to devices switching on/off often, and revising the corresponding hardware/software co-design. Moreover, we can reduce the embodied carbon footprint by using networking hardware longer, and we argue that this could even be beneficial for reliability! We sketch our first ideas in these directions and outline practical challenges that we (as a community) need to address to make the Internet more sustainable.