  The Science Demilitarized Zone (Science DMZ) is a network environment
optimized for scientific applications. A Science DMZ provides an environment
mostly free from competing traffic flows and complex security middleware such
as firewalls or intrusion detection systems that often impede data transfer
performance. The Science DMZ model provides a reference set of network design
patterns, tuned hosts and protocol stacks dedicated to large data transfers and
streamlined security postures that significantly improve data transfer
performance, accelerating scientific collaborations and discovery.
  Over the past decade, many universities and organizations have adopted this
model for their research computing. Despite becoming increasingly popular,
there is a lack of quantitative studies comparing such a specialized network to
conventional production networks regarding network characteristics and data
transfer performance. We strive to answer the following research questions in
this study: Does a Science DMZ exhibit significantly different behavior than a
general-purpose campus network? Does it improve application performance
compared to such general-purpose networks? Through a two-year-long quantitative
network measurement study, we find that a Science DMZ exhibits lower latency,
higher throughput, and lower jitter behaviors. However, we also see several
non-intuitive results. For example, a DMZ may take a longer route to external
destinations and experience higher latency than the campus network. While the
DMZ model benefits researchers, the benefits are not automatic - careful
network tuning based on specific use cases is required to realize the full
potential of such infrastructure.
