If you're interested in datacenter networking, can't miss ONS. Amin Vahdat, the guy in charge of networking at Google, has keynoted the past two years, with hardware in 2015[1] and software in 2014[2]. Mark Russinovich also spoke about Azure's SDN, but it doesn't come close to Amin's presentation.
Every once in a while you'll hear some random spec from one of these companies, and it's always pretty surprising, but Amin's team has achieved 5 Petabit/s in bisectional bandwidth. It's more than surprising.