php command

is there a command that will allow me to connect to another box and execute commands? for instance, I want to create an automated php script that will connect to a unix box and run a series of commands. I believe that ssh2_exec() and ssh2_shell() are not supported in the 4.3.4 version of php I am running. I thought of exec(); i could telnet in to the box but I didn't know if another exec() statement would pass the aurguments to the original telnet session set up in a previous exec() statement.