8 VoIP channels- 4 ports of InMail/VRS with 2 InMail storage hours- 4 Mobile Extension Clients- Telephony Resources – for DTMF, Dial Tone/Busy Tone detection, and FSK Caller ID receiver/sender- Tone Sender – for system tones and DTMF- Conference Resources- Contains:- Ethernet port RJ45- Connector for VoIP Daughter Board VOIPDB – required for additional VoIP channels up to system max of 128- Connector for Expansion Card EXIFB- Connector for SD card for additional InMail storage- Slot for memory backup battery CR2032, included- Installs in dedicated CPU/EXFE slot in Main Chassis