Click to Call allows you to make calls (via Nimbus Assistant UI) by clicking on specifically prepared HTML links. The same kind of link can also pull a colleague or an external number into your ongoing call as a consultation, so you don't need to open the transfer dialog and search for the target manually.
PRECONDITIONS
- Enterprise Routing Contact Center Licensing - "Click to Call" links make use of Outbound Service Call / Call On Behalf as a Enterprise Routing or Contact Center licensed feature. Additionally, the "Outbound Conversations" option must be enabled in the respective service's Modalities Settings Tab for the service to be selectable for Outbound Calls (e.g. within Nimbus Assistant).
-
Nimbus Assistant Installation - This feature requires the Nimbus Assistant App to be installed on each user PC. This will register nimbus-call protocol within the user's PC so Nimbus Assistant can recognize the call as a Nimbus session. The
consultprotocol is not registered by the installer. Your administrator registers it separately on each user PC, as described in the "Troubleshooting and Tips" chapter below. - PSTN Licensing - If you are calling to PSTN numbers via Click to Call, your outbound service also needs a PSTN number applied via the General Service Settings. Contact your administrator if you require a number and related PSTN license. Note that these licenses cost are handled by Microsoft and are outside of Luware Nimbus scope.
- User Licensing - Nimbus users must be members / agents of this service to have it as a selection option before making the call.
Supported link variants
Please note that Nimbus Assistant supports the following protocols:
-
To prefill the target field:
tel:<target>callto:<target>nimbus-call:<target>
-
To start a call directly:
tel:<target>:<serviceId | service UPN>callto:<target>:<serviceId | service UPN>nimbus-call:<target>:<serviceId | service UPN>
-
To start a consultation on your ongoing call:
consult:<target>
💡 All supported protocols are explained below in various examples. To register tel and callto protocols permanently on the Nimbus Assistant app, refer to the “Troubleshooting and Tips” chapter below.
The following link variants are supported:
Variant A: Nimbus call protocol - Outgoing call without service preselected
In this variant the user can click a link, then needs to select a service to call on behalf of in the Nimbus Assistant UI:
<p>This is the standard Nimbus service call protocol and should open Nimbus Assistant dialpad.</p></br>
<a href="nimbus-call:+41791234567">
Nimbus Call to +41791234567 without Service preselected
</a>
<br/><br/>
<a href="nimbus-call:mwinter@lunifico.com" >
Nimbus Call to UPN mwinter@lunifico.com without Service preselected
</a>
<br/><br/>Variant B: Nimbus call protocol - Outgoing call with service preselected for impersonation
In this variant the user can click a link and the service to call on behalf of is already preselected in the Nimbus Assistant UI:
<p>This is the standard Nimbus service call protocol and should open Nimbus Assistant dialpad
with a service preselected.</br>
This example uses Nimbus Service: "contact.center.uk@lunifico.com".
Adapt to your service UPN as needed.</p>
<a href="nimbus-call:+41791234567:contact.center.uk@lunifico.com">
Nimbus Call to +41791234567 with Service
</a>
<br/><br/>
<a href="nimbus-call:a6c49c4b-ac44-4b52-ba4b-ea8c95e9c28c:contact.center.uk@lunifico.com" >
Nimbus Call to a microsoftTeamsUserId with Service
</a>
<br/>Variant C: MS Teams default callto / tel protocols - handled outside of Nimbus
Of course you can still use the default MS Teams functionality and baseline call protocol. These calls are not reflected in the Nimbus UI and not subject to Reporting.
<p>This is the standard MS Teams direct call protocol and should initiate a Teams call.</p>
<a href=callto:+41791234567 >
Teams Call to +41791234567
</a>
<br/><br/>
<p>This is the old MS Teams direct call protocol and should initiate a Teams call if configured locally.</p>
<a href=tel:+41791234567 >
Teams Call to +41791234567
</a>🔍 Read the section below to register Nimbus Assistant as the default for these protocols.
Variant D: Nimbus consult protocol - Consultation call on your ongoing call
In this variant the link carries only the target. What happens when the user clicks it depends on whether they are currently in a call:
| Situation | What happens |
|---|---|
| Connected call | A consultation call to the target starts immediately on your current call. The usual consultation options (merge, swap, transfer, hang up) are available, just like a consultation started from the transfer dialog. If the target is a service, the consultation goes to that service. If the target can't be found (e.g. an unknown UPN), the consultation dialog opens with the target prefilled instead. |
| No ongoing call | No call is placed. The outbound dialpad opens with the target prefilled, the same as in Variant A. You select the service to call on behalf of and start the call yourself. |
<p>This is the Nimbus consult protocol. During a call it starts a consultation,
otherwise it opens the Nimbus Assistant dialpad with the target prefilled.</p>
<a href="consult:+41791234567">
Consult +41791234567
</a>
<br/><br/>
<a href="consult:mwinter@lunifico.com">
Consult UPN mwinter@lunifico.com
</a>
<br/><br/>
<a href="consult:contact.center.uk@lunifico.com">
Consult the Nimbus Service contact.center.uk@lunifico.com
</a>
<br/>☝ IMPORTANT — Consult links
-
Target only: a
consultlink never carries a service. Any additional part after the target is ignored. - Audio calls only: a direct consultation is only started on a connected audio call. For any other task type the link opens the dialpad with the target prefilled.
- When a link is ignored: the click has no effect if you are in RONA, have no connection, already have a consultation in progress, or your call is on hold or being transferred.
- Target format: same as for the other variants: a phone number (E.164), a UPN or a Microsoft Teams user ID. An empty or invalid target shows an "incorrect format" warning.
Troubleshooting and Tips
🤔 Click to Call not working?
Installing the latest Nimbus Assistant App should create new entries for the nimbus-call protocol within the windows registry.
Click here for troubleshooting steps...
1. First, ensure that all preconditions are met, in particular your installed version of Nimbus Assistant.
2. Open the registry editor (Start > Run > Regedit) to ensure that the key has been registered:
Computer\HKEY_CLASSES_Root\nimbus-call
3. Once installed, prepare a mini-HTML site to test your links, using the variant scenarios described above.
4. Clicking on a prepared link should detect the Nimbus protocol and associated it with Nimbus Assistant:
5. The call window should now open with the correct name/number and "Outbound Service" shown
6. Note that the "Outbound Service" will only be selectable for users (members) assigned to that service and if the service is enabled for the Outbound call direction (🔍 see Service Administration > Service Settings).
💡 If the link points to an invalid or user-foreign service the pulldown will show the first available service entry instead.
7. Other things to check when clicks on a link are not working:
- Nimbus Assistant App not running in the background.
- Wrong number (format) - Expecting E.164.
- Permissions on the target machine missing (e.g. Windows registry keys are missing or the App was not installed correctly).
-
consultlinks not opening Nimbus Assistant at all: theconsultprotocol has not been registered on this PC (see setup steps below). -
consultlink opens the dialpad instead of starting a consultation: you were not in a connected audio call, or the target could not be found.
🤔 Can I register Nimbus Assistant as default for callto and tel protocols?
Yes, however some registry keys have to be set for Nimbus Assistant in order to register as an application that supports these protocols.
🤔 Can I register Nimbus Assistant as default for callto and tel protocols?
Yes, however some registry keys have to be set for Nimbus Assistant in order to register as an application that supports these protocols.
Show me the necessary setup steps....
1. Start a new text file that will act as your registry key import, e.g. "Nimbus AssistantProtocolRegistry.txt"
2. Edit the text file and add the following contents:
Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\SOFTWARE\Classes\callto]
@="URL:callto"
"URL Protocol"=""
[HKEY_CURRENT_USER\SOFTWARE\Classes\tel]call
@="URL:tel"
"URL Protocol"=""
[HKEY_CURRENT_USER\SOFTWARE\Classes\NimbusClient.callto]
[HKEY_CURRENT_USER\SOFTWARE\Classes\NimbusClient.callto\Shell]
[HKEY_CURRENT_USER\SOFTWARE\Classes\NimbusClient.callto\Shell\Open]
[HKEY_CURRENT_USER\SOFTWARE\Classes\NimbusClient.callto\Shell\Open\Command]
@="\"C:\\Program Files\\Luware AG\\Nimbus Assistant Client\\Nimbus Assistant.Client.exe\" \"%1\""
[HKEY_CURRENT_USER\SOFTWARE\NimbusClient]
[HKEY_CURRENT_USER\SOFTWARE\NimbusClient\Capabilities]
"ApplicationDescription"="NimbusClient"
"ApplicationName"="NimbusClient"
[HKEY_CURRENT_USER\SOFTWARE\NimbusClient\Capabilities\URLAssociations]
"callto"="nimbusclient.callto"
"tel"="nimbusclient.callto"
[HKEY_CURRENT_USER\SOFTWARE\RegisteredApplications]
"NimbusClient"="Software\\NimbusClient\\Capabilities"☝ Note that the path to 'Nimbus Assistant.Client.exe' has to be adjusted if NA is not installed in the default directory.
3. Rename your text file to a ".reg" file extension and import it to your registry. Afterwards, restart your machine.
4. After a restart, NA will show up in the "Default Apps" system settings of Windows, where it can be assigned as the default application for 'tel:' and 'callto:' protocols:
5. Afterwards, links containing the prefixes will be opened directly in Nimbus Assistant.
🤔 How do I register the consult protocol?
The Nimbus Assistant installer does not register consult links. Your administrator registers the protocol on each user PC, either with a registry import file or centrally via Group Policy or a software distribution tool.
Show me the consult protocol setup steps...
1. Start a new text file that will act as your registry key import, e.g. "NimbusAssistantConsultProtocol.txt".
2. Edit the text file and add the following contents:
Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\SOFTWARE\Classes\consult]
@="URL:consult"
"URL Protocol"=""
[HKEY_CURRENT_USER\SOFTWARE\Classes\consult\Shell]
[HKEY_CURRENT_USER\SOFTWARE\Classes\consult\Shell\Open]
[HKEY_CURRENT_USER\SOFTWARE\Classes\consult\Shell\Open\Command]
@="\"C:\\Program Files\\Luware AG\\Nimbus Assistant Client\\Nimbus Assistant.Client.exe\" \"%1\""☝ Adjust the path to 'Nimbus Assistant.Client.exe' if NA is not installed in the default directory.
3. Rename your text file to a ".reg" file extension and import it to your registry.
4. Test the registration with a prepared consult link (see Variant D above). Clicking it should open Nimbus Assistant.
💡 To roll this out to many PCs, deploy the same registry keys via Group Policy (Registry preference items) or your software distribution tool instead of importing the file on each PC.
🔎 Click to Call in other areas
- Protocol links do work in other applications. Have a look at our Use Case - Adding a Nimbus Click to Call button in Salesforce.
-
Click-to-Call methods - aside from using Assistant with URL protocols, there are also other means to also start an Outbound “Call on Behalf". For example…
- Via Nimbus API, using the “POST Start a Call on Behalf” method.
- Via Power Automate “Start a call on behalf” Flow Action.