Help using ConnectToTCPServer function for connecting to a printer

Hello,

I am attempting to communicate to a printer using the following function:

int ConnectToTCPServer (unsigned int *conversationHandle, unsigned int portNumber, char serverHostName[], tcpFuncPtr callbackFunction, void *callbackData, unsigned int timeOut);

For the serverHostName, I am using the IP address of the printer. However, I am confused as to what number to put for the port number. How do I obtain this information?

Thanks!