Different clients might use a single connection or two connections for returned data.
The REXEC client (RUNRMTCMD) uses a single connection for returned data, which is written to a spooled file on the client.
The UNIX®, OS/2®, and Windows® REXEC clients all use two connections, returning the normal output to the stdout stream and the error output to the stderr stream.
The VM REXEC client uses a single connection for the returned data, which is written to the console of the user.