Grandstream UCM 6204 IP PBX

Quick Info:

  • Onsite IP PBX with PSTN connectivity
  • CRM and PMS integration available
  • Smartphone integration for Android & iPhone
  • designed for Office, Call Center & Hospitality
  • small & medium setups

Compatible with:

  • Bangkok, Thailand DID Numbers
  • Grandstream, Yealink, Snom, Fanvil IP Phones

Designed for:

  • businesses with advanced needs
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The Grandstream UCM 6204 is designed to bring enterprise-grade voice, video, data, and mobility features to small-to-medium sized businesses. The Grandstream IP PBX is geared towards small to medium sized offices as well as Contact Centers. The device is ideal for companies that require advanced features like Hot-desking, FAX to email, listening in to calls for quality control etc. The IP PBX even allows connecting up to 4 analogue PSTN lines to the IP PBX allowing you to receive incoming calls on existing phone lines and use these lines for outbound calls in case of Internet failure. Last but not least you can interconnect Video phones and CCTV and control everything from one device or even remotely from anywhere.

More key features include:

  • Call recording allows you record all incoming and outgoing calls on defined extension phones
  • Conference Room: Arrange 3 virtual meetings with up to 25 participants
  • Call Detail Record shows all incoming, outgoing and missed calls
  • Ring Groups:  Assign different departments (like Sales, Support, Accounting of your company into ring groups
  • Music on hold: When transferring calls of your customer to other extensions or putting them on hold your clients will listen to music
  • HD Telephony lets you make phone calls in crystal clear voice quality
  • Message Waiting Light: A light on the IP Phone indicates left voicemail messages
  • The Busy Lamp field indicates the status of other extension phones in the system ( busy, ringing, available) for the Front desk manager
  • Video Telephony:  Connect the Grandstream GXP 3275 or GXP 3240 to make Video calls
  • Call pickup:  Take a call for someone else at your extension phone
  • 500 Extensions: The Grandstream UCM 6204 can support up to 800 extension phones
  • Concurrent calls: up to 45 people can make and receive calls at the same time
  • Blacklist callers: allows you to blacklist phone numbers from unwanted callers
  • Listening in on calls: Normal Spy, Whisper Spy, Barge Spy
  • Skype integration: via Skype SIP connect
  • Intercom: call an extension phone  and the phone will automatically go to speaker phone
  • DND: ( Do not Disturb) Press a key on the phone and is will stop ringing
  • Voicemail 2 email: left voicemails will automatically forwarded to your email inbox
  • Office hours: The phone system can automatically change to voicemail when office hours are defined
  • Holidays: The phone system can automatically play customized messages on Holidays
  • Music on hold: When customers are put on hold they will listen to music
  • FAX2email: receive incoming Faxes to your email Inbox
  • Send Faxes: Send Faxes from the Interface of UCM 6204
  • Call Queues: Send incoming calls into a call queue if all lines are engaged
  • Ring Groups: Define ring groups in a company department
  • Hot-desking: If you have staff working in shifts they can work from any desk. They just log in with their extension. If they finish work they log out again and the desk is available for the next worker

Interfaces & Technical Data:

  • Form factor: Desktop: L 226 mm x W 155 mm x H 34.5 mm
  • 1x 128×32 graphic LCD Display
  • 1x USB port, 1x SD Card Slot
  • 2x LAN ports 10/100/1000
  • 2x FXS ports to connect analogue telephones
  • 4x FXO ports to connect analogue (PSTN) telephone lines
  • Supports up to 500 extensions and up to 45 concurrent calls
  • Up to 50 SIP trunk accounts can be registered
  • VoIP codecs: G7.22 (wideband audio or HD)
    G.711 U/A (ISDN quality) G.7.29A/B, G.7.26, G.7.23
  • Video Codecs H.264, H.263 (Video Telephony)
  • Fax codecs: T.38, G.7.11U/A
  • Power Consumption: 10 watts


Onsite / Hosted


Max extensions


Max concurrent calls


Max SIP Trunk registrations

up to 50

FXO ports (PSTN)


FXS ports (Phones)


BRI ports (ISDN)

via sepearate Gateway

GSM/3G/4G Gateway

via sepearate Gateway

PRI / E1 port built-in

via sepearate Gateway

Virtual conference bridges

up to 25 participants





Smart phone integration


Call Reporting (CDR)


Fax sending / receiving

Supported / Supported



Call Recording

Virtual Assistant (IVR)

Multi-level IVR

Hot Desking


Music on Hold


PMS Integation

Currently not avalialbe

Call Center features

Basic features integrated



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