### Requirements and Considerations

#### Requirements

- The RealPort driver requires between one and two MB of memory on the Microsoft Windows 2000 system.
- The Windows 2000 RealPort driver requires a 10-pin RJ-45 cable to connect devices to PortServer ports. This requirement does not apply to Etherlite units.

#### Limitations

- Only TAPI-compliant applications or those written to COM 32 API (application programming interface) standards can use intelligent ports, which means only these applications can use RealPort ports.

#### Key Concept: About Port Mapping Offsets

The number of local ports on the Windows 2000 host offsets the port number on the PortServer. For example, if you have two local COM ports, Port 1 of the Digi One RealPort or PortServer is seen by the RealPort service as COM 3.