SoNIC: Precise Realtime Software Access and Control of Wired Networks

The physical and data link layers of the network stack contain valuable information. Unfortunately, a systems programmer would never know. These two layers are often inaccessible in software and much of their potential goes untapped. In this paper we introduce SoNIC, Software-defined Network Interface Card, which provides access to the physical and data link layers in software by implementing them in software. In other words, by implementing the creation of the physical layer bitstream in software and the transmission of this bitstream in hardware, SoNIC provides complete control over the entire network stack in realtime. SoNIC utilizes commodity off-the-shelf multi-core processors to implement parts of the physical layer in software, and employs an FPGA board to transmit optical signal over the wire. Our evaluations demonstrate that SoNIC can communicate with other network components while providing realtime access to the entire network stack in software. As an example of SoNIC’s fine-granularity control, it can perform precise network measurements, accurately characterizing network components such as routers, switches, and network interface cards. Further, SoNIC enables timing channels with nanosecond modulations that are undetectable in software.