DICOM being a protocol of its own, it used to be a touch one to implement over the internet. A workaround consisted in using VPN tunnels to connect PACSs in different networks.
DICOMweb is the Web standard for medical imaging. It is primarily a set of RESTful services.
Out-of-the-box, Orthanc comes with its own REST API. This API allows full CRUD operations (create, read, update and delete) on the set of DICOM resources that Orthanc stores, together with commands that trigger calls to the DICOM protocol (C-Echo SCU/SCP, C-Store SCU/SCP, C-Find SCU/SCP, C-Move SCU/SCP).
The present plugin extends the native REST API of Orthanc with a reference implementation of the DICOMweb standard. Loading the plugin into Orthanc will provide support of WADO-URI (previously known simply as WADO), WADO-RS, QIDO-RS and STOW-RS.