When a composite network node is providing RTP-level support as a session endpoint, a session must enter or exit the composite network node through VTAM® to use HPR. HPR routing is not used when a session traverses such a composite network node through NCP (in through NCP, out through NCP). In Figure 1, for example, HPR is not used for a session between LUC and the terminal that traverses the connection between the two NCPs. However, HPR is used between VTAMs for the same session if it traverses the connection between the two VTAMs. HPR is also used between VTAMs for a session between LUA and the terminal.