Planar-attached asynchronous ports
Most system unit models have two integrated (standard) EIA 232 asynchronous serial ports. EIA 232 asynchronous serial devices can be attached directly to the standard serial ports using standard serial cables with 9-pin D-shell connectors.
Some multiprocessor systems have a third serial port used for communication to the remote service center.
Note: Itanium-based systems have one or two integrated serial ports.
Initial workstation models have one port, while the initial server
class models have two ports.