If the session endpoint in the APPN network is an end node or network node that is more than one hop away from the interchange node, translation of subarea to HPR can occur if the interchange node is IBM® Communications Server for OS/390® V2R10 or later and the adjacent network node is one of the following types:

• A network node with IBM Communications Server for OS/390 V2R10 or later installed
• A non-z/OS® Communications Server network node

Note, however, that the RTP connection will only extend from the interchange node to the adjacent network node. An additional, separate, RTP connection can be established for the remainder of the APPN session path (depending on the HPR and RTP capabilities of the nodes on the path), but a single end-to-end RTP connection between the interchange node and the APPN session endpoint will not be used. In Figure 1, for example, HOSTD is part of a subarea network connected to an APPN network through HOSTC. In the case of a session between LUD and LUA, one RTP connection can be established between the HPR-capable endpoints HOSTC and HOSTB, and a second RTP connection can be established between HOSTB and HOSTA. Of course, for sessions between LUC and LUA, a single end-to-end RTP connection can be used between HOSTC and HOSTA (through HOSTB).