DTNs should run the appropriate data transfer tools for their environment. Examples of capable general-purpose tools are Globus and Aspera, and there are more domain-specific tools such as XRootD and bbcp. The data transfer tool selection process should include criteria such as performance, ease of use by scientists, compatibility/interoperability with community and collaborator DTNs, security, and sustainability/maintainability.
In addition, the perfSONAR tools are quite useful for DTN performance tuning. Instructions for installing the perfSONAR tools is available here.