Pure IP PBXMax number of analogue trunks: 12Preinstalled analogue trunks: 6Max number of ISDN trunks: 4Max 64 VoIP TrunksMax. 128 analogue extensionsPreinstalled analogue extensions: 16Max number of PT's: 66Preinstalled PT ports: 2Compatible PTs: DT5xx/ DT3xx/ T7xx seriesMax number of door openers: 8CLIP on internal calls: YesCLIP on incoming calls: YesExtension number change: Yes3 layer DISA with OGM: Yes3 party conference calls: YesSpeed dialing: YesSecond call acceptance: YesCall forward: YesCall transfer: YesCall park: Yes"Do not disturb" mode: YesTime schemes: 3Call waiting: YesExtension locking/ unlocking: YesMusic on hold: YesEmergency power interface: YesAutomatic call routing: YesOptional DECT Cell stations: YesRemote access: YesMemory protection while power off: YesProgramming via...: WebOperating temperature: 0C up to 40COperating humidity: 5% - 90%