KX-TDE600 Pure IP PBX Control Unit is an advanced communication platform for IP Networking Environments with support for desktop SIP connectivity and a range of advanced IP telephones as well as digital extensions and ISDN trunks. IP PBX Control Unit Features: Support small to large communication system Integrated SIP telephony via Internet Telephony Service Providers (ITSP) and other SIP trunk Providers Built-in support for Advanced IP extensions as well as standard SIP phones IP Phones and Soft phones for Remote Workers and Road Warriors Desktop, Network, and Business Application Integration Business Productivity with Wireless Mobility Solutions Easy Migration (Upgrade from Hybrid TDA to Pure IP TDE PBX) Built-in Voice Mail - with option to upgrade using KX-TVM50, TVM200 Reduced Total Cost of Ownership (Installation and Network call costs reduced) Centralized Management and Upgrades Maximum Extension Port (DPT and SLT and IP Extension): Without DXDP: 368 With DXDP: 432 Physical Extension Cards: Single Line (a/b) Telephone (SLT): 240 Digital Proprietary Telephone (DPT) - Type 1 (With DXDP): 256 Digital Proprietary Telephone (DPT) - Type 2: 128 IP Proprietary Telephone (IPT): 160 Analog Proprietary Telephone (APT): 80 Direct Station Select (DSS) Console: 64 Voice Processing System (VPS): 8 Virtual Extension Cards: SIP Extension: 128 IP Proprietary Telephone (IPPT): 64 Trunk Port: 192 Physical Trunk Cards: ISDN Trunk (BRI): 160 ISDN Trunk (PRI): 150 Analog Trunk: 160 IP Gateway: 160 Virtual Trunk Cards - SIP Trunk: 32 Wireless Portable Station (PS): 512 Wireless Cell Station (CS): 32 Doorphone Port: 16 Door Opener: 16 External Sensor: 16 External Relay: 16 USB Module: 160