These both sit on top of OpenCloud’s Rhino SIS product.
These services each contain features for IMS Service Centralisation. Of note are the Reorigination features. One sits in the Sentinel IN service, and the other in the Sentinel SIP service. Reorigination data is stored in the Correlation RA.
More information on these features is described in the VoLTE Administration Guide, under the Service Centralisation Features.