What is CloudUCM?

CloudUCM is a cloud-based PBX that requires no hardware for deployment, significantly reducing maintenance costs. IP phones and Wave can connect to CloudUCM from anywhere as long as they are connected to the Internet and can be used for audio calls/video calls/meetings, allowing people around the world to easily collaborate with one another.

For more details, please refer to:

What is the difference between CloudUCM and UCM?

While both CloudUCM and UCM are stable and efficient phone systems with their own advantages, CloudUCM has the following benefits:

  • Cost-Savings: CloudUCM services are on cloud servers, significantly reducing on-premises deployment and maintenance costs.
  • Scalable: Easily expand your phone system capabilities as your business evolves without complex professional maintenance.
  • Flexible Remote Office: Empowers employees to work remotely and communicate effortlessly from anywhere with any device.
  • High Availability: 99% availability of services through AWS and immune to local disasters and outages.
  • One-stop Work Platform: With CloudUCM, you have a comprehensive add-in ecosystem, integrating rich CRM systems, Live Chat, WhatsApp, MS Teams, Hot desk and other collaborative add-ins, as well as support for custom internal add-ins for companies.

What to look for in a cloud PBX provider?

The following are essential features of a good cloud PBX provider:

  • Do you need any advanced features in addition to the standard phone system features?
  • Do they support remote working and mobile working?
  • Do they allow you to integrate your system with 3rd party platforms and provide easy-to-use add-ins?
  • Do they offer cloud PBX services as part of a unified communications solution, enabling users to take their experiences to the next level with features such as comprehensive remote management of PBX and VoIP devices?
  • Do their cloud servers provide a stable and reliable service?
  • Do they place their servers in geographically dispersed data centers?
  • Do they have the ability to integrate with your existing trunk server?
  • Do they provide ongoing customer support and system updates?

CloudUCM has all of these features above.

What is the total cost of ownership of CloudUCM?

CloudUCM converts capital expenditures into operating expenditures.

  • Minimum initial investment is required to get started. Aside from IP endpoints, you would only pay an ongoing subscription fee every year.
  • With SIP trunk features, you have the flexibility to choose service providers based on your own budget and needs.
  • No maintenance costs. For small businesses with limited resources, CloudUCM does not require dedicated IT staff to manage and maintain the system.

Do I need to purchase the UCM RemoteConnect plan for my CloudUCM?

No. RemoteConnect features are already included with your CloudUCM purchase. UCM RemoteConnect is a cloud service for physical UCMs that allows system administrators to remotely and securely access their systems without complex firewall configurations.

How is the number of concurrent calls calculated?

Concurrent calls are calculated assuming a call between a caller and callee counts as a single call. In contrast to the way UCMRC remote calls counts the caller and callee lines as two separate calls if both parties are registered via UCMRC, the same call would be counted as only one call with CloudUCM.

Note: In an N-way conference, each party would count towards the concurrent call limit (e.g., three N-way conference members would count as three concurrent calls).

Is there a limit on the number of concurrent registrations per extension?

Yes. Please refer to the Plan Specifications page to see the concurrent registration limits of each plan. While any SIP endpoint/softphone client can register to a CloudUCM extension as long as it doesn't exceed the concurrent registration limit, each extension can have only one Wave PC registration and one Wave Mobile registration.

Will emergency calls via CloudUCM be restricted by CloudUCM plan specifications?

No. The call duration and concurrent number of emergency calls are not restricted by any CloudUCM plan specifications. 

How do I quickly configure CloudUCM service on IP phones?

Method 1: For Grandstream endpoints only:

Add the Grandstream IP phone to GDMS. Look for the newly added phone on the VoIP Device page. In the Options column for that phone, click on the button to enter the Account Configuration page. Select the desired CloudUCM extension and save your settings.

Method 2: If the endpoint is not on GDMS, cannot be added to GDMS, or is from another manufacturer, you can register it to CloudUCM by configuring the settings in the following table.

For more details, please refer to the document How to Configure CloudUCM on IP Phones.

Account Settings->Basic Settings
SIP Server
CloudUCM SIP Server Address.
This information can be found under UCM
Web GUI->CloudUCM Plan page.
Note: Must include port number. By default, UDP/TCP is 5060, and TLS is 5061.
Enter the desired extension on the CloudUCM.
Enter the extension’s SIP password.
NAT Traversal
DNS Mode (Optional)
DNS SRV Failover Mode (Optional)
Use current server until no response
Account Settings->SIP Settings
(Optional. While TLS is recommended, UDP and TCP are also supported)
SIP Transport
Supports TLS/UDP/TCP. It is recommended to use TLS or TLS/TCP for security reasons.
Account Settings->SIP Settings
(Optional. If your network environment is not stable, configuring these is recommended.)
REGISTER Expiration (m)
50 (TLS or TCP)
3 (UDP)
Enable Session Timer
Session Expiration (s)
Min-SE (s)
Caller Request Timer
Callee Request Timer
UAC Specify Refresher
UAS Specify Refresher
Security Settings->TLS Settings
Minimum TLS Version
1.2 or 1.3
Maximum TLS Version
1.2 or 1.3


What happens if the CloudUCM plan expires?

When the CloudUCM plan expires, your CloudUCM will stop running and can no longer be used. We will temporarily preserve the data in the cloud server for up to 30 days, during which you can renew your plan. Please be mindful of plan expiration dates and renew at your earliest convenience.


How do I purchase CloudUCM plan?

CloudUCM subscription plans are sold by authorized resellers. You can place orders for CloudUCM plans by contacting your Grandstream equipment reseller.


How do I apply for a CloudUCM trial?

You can sign in to the GDMS to request a trial or contact your Grandstream equipment reseller.

If I purchase a CloudUCM plan but have not activated the CloudUCM device, when will the plan take effect?

The plan will not take effect until the CloudUCM device has been activated. For example, if you purchase a 1-year Plus plan on April 2nd, 2024, and the device is not activated until May 5th, 2024, the plan will take effect from May 5th, 2024 up to May 5th, 2025.

Can I batch order plans and activate them only when end users have confirmed the orders?

Yes. Since CloudUCM plans take effect only when the CloudUCM devices are activated, there is no cost or fee for holding plans for unactivated devices. Additionally, this allows for quick responses to customer requirements.

Can a single CloudUCM plan be assigned to multiple customers?

No. Each CloudUCM device is a cloud PBX virtual machine with its own separate storage space for data and files. Sharing a CloudUCM with other customers may result in fatal security and privacy breaches. A channel reseller can purchase a CloudUCM plan for each customer separately based on their deployment requirements such as the number of extensions and concurrent calls (see CloudUCM Plan Specifications).

If my CloudUCM trial has expired, can I renew the plan for this CloudUCM device and continue using it?

Yes. You would need to subscribe to the CloudUCM plan for this CloudUCM to continue using it.

What if the storage space of my CloudUCM is almost full?

You can set up regular storage cleanup through the CloudUCM’s Maintenance page or purchase an add-on plan to expand your storage space.

What happens if my CloudUCM plan is downgraded, and the number of extensions or storage space exceeds the new plan's limits?

If the existing number of extensions exceeds the max limit of the new plan, the excess extensions will need to be deleted within 7 days. Otherwise, all extensions will be disabled and cannot be used. If the storage space usage exceeds the max limit of the new plan, several CloudUCM services such as calling, and meetings will become inaccessible until the excess data is cleared.

Does a newly purchased CloudUCM device need to be activated before use?

Yes. Otherwise, you will not be able to use it. You can activate a CloudUCM on GDMS or click the activation link in the CloudUCM activation email. Once activated, the CloudUCM will be running and accessible for management.

How can customers access their CloudUCM systems?

There are two ways:

Method 1: Customers can directly enter the CloudUCM’s address into their address bar (e.g. to bring up the CloudUCM management portal.

Method 2: The channel reseller can create and assign a sub-account on GDMS to each customer, and the customer can log into GDMS with those accounts and access their CloudUCM.

Can I add the CloudUCM device to the GDMS platform for remote management?

Yes, you can use the MAC address of the CloudUCM device and its initial password to add it to GDMS platform for remote management such as syncing extensions to it, remotely accessing the CloudUCM management portal, upgrading firmware, rebooting, resetting to factory, and etc.

Can I use the CloudUCM server address for trunk registration?

Yes. CloudUCM supports register trunks, peer trunks, and WebRTC trunks.

  1. On the PBX Settings -> SIP Settings -> Transmission Protocol page, you can enable all transport protocols needed for your trunks. Only TLS is enabled by default.

  2. Peer Trunk:
    a. You need to configure Provider Name, Host Name, and Transport.
    b. If the other party is a CloudUCM, the host name would be the domain address of the CloudUCM, and you will need to enable the Domain Connection Mode.
    c. If t
    he other party is a UCM63xx with UCMRC services, the host name is the UCMRC domain address of the UCM63xx device with the port number (5061), the transport protocol is TLS, and you will need to enable the Domain Connection Mode.

  3. Register Trunk:
    a. You need to configure Provider Name, Host Name, Transport, Registration Number, and Password.
    b. If the other party is a CloudUCM, the host name is the domain address of the CloudUCM.
    c. If the other party is a UCM63xx with UCMRC services, the host name is the UCMRC domain address of the UCM63xx device with the port number (5061), and the transport protocol is TLS.

How does CloudUCM integrate with the trunk server?

CloudUCM supports integrating and deploying with PSTN Analog Trunks and SIP Trunk Providers under private and external networks and supports mutual Trunk registration with other UCMs/CloudUCMs. Please refer to the CloudUCM Deployment Scenario Instructions for more details.

Does CloudUCM support HA features?

Currently not supported. HA redundancy between CloudUCM and UCM63xx/CloudUCM is in the future plan.

Is it possible to manage CloudUCM devices separately for multiple customers on the GDMS platform?

Yes. You can create multiple organizations or sites on the GDMS platform to manage CloudUCM for your customers. For different customers, it is recommended to create multiple organizations and add CloudUCMs for different customers to different organizations for management. Each organization has its own CloudUCM devices, VOIP devices, extensions, tasks, and other data.

If a customer needs different CloudUCMs under one organization to be managed by separate departments, you can create multiple sites under the organization and add CloudUCMs to those different sites for management.

For more details, please refer to the CloudUCM Multi-tenant Management User Guide.