Autonomous NIC offloads
Boris Pismenny, Haggai Eran, Aviad Yehezkel, Liran Liss, Adam Morrison, Dan Tsafrir
Abstract
CPUs routinely offload to NICs network-related processing tasks like packet segmentation and checksum. NIC offloads are advantageous because they free valuable CPU cycles. But their applicability is typically limited to layer≤4 protocols (TCP and lower), and they are inapplicable to layer-5 protocols (L5Ps) that are built on top of TCP. This limitation is caused by a misfeature we call ”offload dependence,” which dictates that L5P offloading additionally requires offloading the underlying layer≤4 protocols and related functionality: TCP, IP, firewall, etc. The dependence of L5P offloading hinders innovation, because it implies hard-wiring the complicated, ever-changing implementation of the lower-level protocols.