CooVox-U20 IP Phone system is the second generation of Mini IP Phone System released from ZYCOO, meanwhile it's the first Mobile IP Phone system with the ability to use the GSM or UMTS (3G) module to connect to the mobile network for data transport.

CooVox-U20 is a next-generation smart IP PBX system designed and optimized for today's business telecommunication needs.

CooVox-U20 is an affordable, scalable, interoperable, secure and reliable solution which not only provides traditional PBX functions such as automated attendant and voicemail, but also many advanced features including remote extensions, remote office connection, conference bridge, call recording, call detail records (CDR), automatic call distribution (ACD), unified messaging (voice mail to email), and many more features.

CooVox-U20-A202 2 0
CooVox-U20-A211 1 1


Call Features
Call Back
Call Forward
Call Hold
Call Paging and Intercom
Call Park
Call Pickup
Call Queue
Call Recording
Call Routing
Blind Transfer
Attended Transfer
Call Waiting
Caller ID
Dial by Name
Music On Hold/Transfer
3-Way Conference
Video Call

PBX Features
Black List
BLF (Busy Lamp Field)
CDR (Call Detailed Record)
Conference Room (3 Rooms)
Call Monitoring
DID (Direct Inward Dialing Number)
DISA (Direct Inward System Access)
Distinctive Ringtone
DND (Do Not Disturb)
DNIS (Dialed Number Identification Service)
Feature Codes
FOP (Flash Operation Panel)
Follow Me
IVR (Interactive Voice Responses)
Mobility Extension
Multi-Language Prompts
Multi-Language GUI
One Touch Recording
Phone Book
Phone Provisioning
Pin Set
Record File Download
SIP Register with UDP/TCP/TLS
SIP Trunk
Skype for SIP
Smart DID
Speed Dial
SRTP (Secure Realtime Transport Protocol)
T.38 Fax (Pass-through)
Time Based Rule
Virtual Fax
Voicemail & Voicemail to Email

System Capacities
10 Concurrent Calls
Up to 30 IP Phone Registers/Extensions
Recording: 21,000 mins (.gsm); 3,000 mins (.wav)
Voicemail: 21,000 mins (.gsm); 3,000 mins (.wav)

Codecs & Protocols
Audio Codecs: G.722/G.711-Ulaw/G.711-Alaw/
Video Codecs: H.261/H.263/H.263+/H.264
Protocols: SIP (RFC3261)/IAX2

Network Features
DDNS Client
DHCP Server
IP Assignment (PPPoE/DHCP/Static)
SNMP v1/v2
Static Route Table
Trouble Shooting (Ping/Traceroute)
PoE (Power over Ethernet)
VPN Client (N2N/L2TP/PPTP/OpenVPN)
VPN Server (PPTP/L2TP/OpenVPN, Up to 10 Users)

Security Features
Refuse SIP Register DoS
Refuse Abort Invite DoS
Refuse SSH Login DoS

Web Access Log
PBX Debug Log


Hardware Interfaces
1 Reset Button
1 Power Interface
1 Ethernet Interface
2 Analog Ports (FXO/FXS)
1 GSM/UMTS Interface (Onboard)

Hardware Specifications
Processor: DualCore 500Mhz DSP
Storage: 4GB SD Card
Power Supply: Input AC 100~240V, 50/60Hz; Output DC 12V/1A

Working Temperature: 0 ~ 40°C
Storage Temperature: -20 ~ 55°C
Humidity: 5 ~ 95% Non-condensing

*PSTN is not perferctly supported temporarily in UK

Applicable Modules

       FXO-200 (2FXO)          FXS-200 (2FXS)     FXOS (1FXO+1FXS)



Inner Box Dimension 280 mm × 150 mm × 62 mm
G.W./Unit 0.8 kg
Carton Dimension 345 mm × 320 mm × 310 mm
Units/Carton 10 Units
G.W./Carton 9 kg


Name Version Size Release date Download
CooVox-U20 Datasheet V1.0 927.89 KB Apr. 15, 2014
CooVox-U20 Firmware V1.0.5 12.76 MB Apr. 26, 2014
CooVox-U20 Firmware Patch V1.0.5 Patch1 751.30 KB May. 22, 2014
CooVox Series User Manual (Admin) V1.0.5 2.94 MB May. 20, 2014
CooVox Series User Manual (Ext. User) V1.0.5 634.75 KB Apr. 16, 2014
CooVox-U20 QIG V1.0 3.00 MB Apr. 17, 2014
CooVox Module Setting Guide V1.0 1.16 MB Apr. 17, 2014