  Large scientific collaborations often share huge volumes of data around the
world. Consequently a significant amount of network bandwidth is needed for
data replication and data access. Users in the same region may possibly share
resources as well as data, especially when they are working on related topics
with similar datasets. In this work, we study the network traffic patterns and
resource utilization for scientific data caches connecting European networks to
the US. We explore the efficiency of resource utilization, especially for
network traffic which consists mostly of transatlantic data transfers, and the
potential for having more caching node deployments. Our study shows that these
data caches reduced network traffic volume by 97% during the study period. This
demonstrates that such caching nodes are effective in reducing wide-area
network traffic.
