Kindly note that there is no official port for debugger. You can select any specific TCP/IP port or a range of ports which are free for the Designer connection to the Integration Service.
To configure debugger ports, goto Designer -> Tools -> Options -> Debug
There is no recommendation for any of the ports that Informatica uses. However you can use any port which is known to be free. And also if required you can assign some default port which your companies follows as best practices and port availability.
The most important thing about the TCP/IP connection for the Debugger is this:
Since PowerCenter 8.1. Service Pack 5, the TCP/IP connection for a debugger session in PowerCenter is not opened by the client PC running the Designer, this port is opened from the server to the client PC. Which means that these ports have to be set up in a firewall such that a TCP/IP connection can not only be opened from client PCs to servers but also from servers to client PCs.
There are two custom properties for the PowerCenter Integration Service which can be used to determine a range of TCP/IP ports on the PowerCenter server node; if not set, these two properties default to the port range 9229 through 9329 (if I recall correctly); in order to restrict the number of TCP/IP ports used for debugging, it is recommended that you define these two custom properties and have all these ports set up in the firewall as described above.