Alternate Communications Path Examples

The following examples show two different ways of using alternate communications paths.


The following is an example of an adjacent node entry that has four alternate communications paths that can be used if the main communication path specified for the adjacent node (TCP/IP address of cannot be used. Three of the alternate communications paths are defined using the ALT.ADDR parameter while one uses the ALT.NODEDEF parameter.

 PARSESS=(6 2) -
          (ALT.NODEDEF=TEST.NODE), -
          (ALT.ADDR=,ALT.PORT=4374,ALT.TYPE=TCP)) -

Restarting Processes using an Alternate Communications Path

In the following example, the adjacent node in the previous example has been redefined to allow an alternate communications path which only supports Version 2 flows. In this system, IBM® Connect:Direct® is running on a machine with two Network Interface Cards (NICs), which means that there are two IP addresses for this machine. On the remote IBM Connect:Direct system, both of these IP addresses are included in the network map adjacent node entry for the original IBM Connect:Direct system.

In this example, assume a Process is started by the remote IBM Connect:Direct to this adjacent node with two NICs. The first path (TCP/IP address of 1364, is selected when the Process establishes its session. For some reason, the NIC fails on the machine, and the Process fails and goes into retry.

If ALT.RESTART=NO (the default), this Process can never restart successfully because it will always use the path used during initial session establishment (in this case, the failed NIC). When ALT.RESTART=YES is specified, the Process will try all ALT.COMM paths and will restart successfully because an additional path is available (ALT.ADDR=,ALT.PORT=4374). ALT.NODEDEF points to another network entry and only uses the primary address for that node. Connection failure using the primary address does not result in running that node's ALT.COMM parameters (assuming it has any).

 PARSESS=(6 2) -
         (ALT.ADDR=,ALT.PORT=4374,ALT.TYPE=TCP))    -