The Siemens optiPoint 420 S familyAll models belonging to the optiPoint 420 S families are based on the SIP protocol (Session Initiation Protocol) for effective communication with all components in the network. This enables the terminal devices to support a multitude of SIP-based communication systems. In addition they are optimized for use of the features of the Siemens HiPath 8000 communication system. Power can be supplied either locally or via Power over Ethernet (PoE) in accordance with the IEEE 802.3af standard.The Siemens optiPoint 420 Advance S model is particularly prestigious: 18 function and 3 dialog keys, full duplex hands-free operation and the large-format, four-line graphical display offers maximum convenience when telephoning. As well as supporting standardized SIP features, the optiPoint 420 Advance S version also supports special functions from the SIP HiPath 8000 platform. This enhanced feature model is rounded off by the option of two slide-in units for expansion with add-on modules. This telephone is particularly suitable for use in management offices, conference rooms and luxury hotel rooms.