The CPU-C1 board is installed into the CPU/EXIFE Slot in the Controlling Chassis and controls all the functions and operations of the SL2100 system using the system software loaded into the CPU-C1 memory. One CPU-C1 board must be installed in the Controlling Chassis The CPU-C1-A provides: – Built-In 8ch VoIP Resources – Built-In 4ch VRS/VM (InMail) capability – 2 hours VRS/VM (InMail) storage without SD Card – Four clients of Mobile Extension – Maximum Four participants of Web Video Conference – One Voice Prompt of VRS/VM (InMail) as default – Default Language: UK English – One VoIPDB daughter board connector – One Ethernet (100M) port (RJ45) – One EXIFB daughter board connector – One SD Card slot (for expand VRS/VM storage) – 4 pcs of SL2100 IP TRUNK-01 LIC and 4 pcs of SL2100 IP EXT-01 LIC are bundled https://www.nec-enterprise.com/