Example 2. IMS-to-IMS application routing

The following figure illustrates IMS-to-IMS routing using an application program in both IMS subsystems.

Figure 1. ISC example for IMS-to-IMS application routing
Message flows from terminal to Basic Edit in Control Region of IMS A, then to TRANX in MPP of IMS A, then to TRANY in IMS B, then to ISCEDT and Default MOD on IMS A, then back to terminal.

The input format from the terminal operator differs from that in Example 1 in that the routing can be supplied by TRANX in IMSA rather than by the terminal operator. Processing in IMSB and on the session is the same as that described for Example 1. Also see Examples 6 and 7 later in this topic to understand the interaction of MFS in the routing scenario.