  In an era of pervasive online surveillance, Internet users are in need of
better anonymity solutions for online communications without sacrificing
performance. Existing overlay anonymity tools, such as the Tor network, suffer
from performance limitations and recent proposals to embed anonymity into
Internet protocols face fundamental deployment challenges. In this paper, we
introduce Practical Anonymity at the NEtwork Level (PANEL), a practical
light-weight anonymity solution based on hardware switching. We implement a
prototype of PANEL on a high-performance hardware switch (namely, Barefoot
Tofino) using P4 network programming language, and examine the validity and
performance of the prototype. Based on our empirical results, PANEL achieves
96% of the actual throughput of the switch and adds a low-latency overhead
(e.g., 3% overhead in Skype calls), while offering partial deployablility and
transparency (i.e., PANEL requires neither client-side nor server-side
modifications).
