If you define links to multiple different VRNs (using different local IP addresses), you can choose different TG characteristics on these definitions to force sessions using different APPN COS names to flow over different VRNs (and use different local IP addresses). You can also configure the IP network to route traffic for different APPN COS names (IP ToS values) using different physical IP interfaces. For example, #INTER traffic could be sent over a Gigabit Ethernet connection and #BATCH traffic could be sent over a slower OSA link.

Using this type of configuration, you can monitor APPN traffic flows by displaying the RTPs that flow through a specific VRN. You can do this by specifying the FIRSTCP=vrnname operand, the FIRSTTG=tgnumber operand, or both on the DISPLAY RTPS command. This configuration also enables you to monitor IP traffic flows by tracing flows based on source or destination IP addresses.

If the APPN product you are using for a remote EE partner does not allow you to define multiple VRNs at the same time, then instead you can define two links to the same VRN at your z/OS® system (using different local IP addresses) and force sessions to be load balanced over those connections. You can still monitor APPN and IP traffic by specifying both the FIRSTCP= and FIRSTTG= operands on the DISPLAY RTPS command in order to see what traffic is flowing over which link.

Finally, you might also want to use only a single local IP address, but still load balance sessions through parallel VRNs. With this type of configuration, it is not possible to monitor IP traffic over each of these connections, because there is only a single local IP address being used. But you would still be able to monitor APPN session traffic over the parallel routes (VRNs) by using the FIRSTCP= and FIRSTTG= operands on the DISPLAY RTPS command. Furthermore, because only a single IP address is being used, this type of configuration might simplify the coordination of system definitions.