The Free On-line Dictionary of Computing (30 December 2018):

High Performance Routing
HPR

    (HPR) Routing designed to work in conjunction
   with APPN Intermediate Session Routing (ISR) network
   nodes.  HPR nodes perform many of the same functions as ISR
   nodes.  For example, HPR nodes use the same method of
   calculating routes based on the Topology Routing Service
   database and class of service tables.  HPR nodes also
   supports such APPN features as connection networks and support
   for parallel transmission groups (TGs).  In the HPR
   architecture, both partner nodes must support HPR for RTP
   connections to take place between the nodes.  If one node
   supports HPR and the partner node does not, then the link will
   support ISR functionality only.

   ["APPN Architecture and Product Implementations Tutorial",
   IBM, GG24-3669-92].

   (1997-05-08)