How Nimbus users relate to MS Teams Client roles

Within the MS Teams Client Nimbus will use your existing structures to authenticate any team members as users of Nimbus.

  • TEAM OWNER Team Owners can add the Nimbus application to their Teams Client when Nimbus Installation is complete. First Service Provisioning and certain changes to Service Settings may require Tenant Administrator assistance.
  • TEAM MEMBERS Team Members act as the main "service" team - simply referred to as users of Nimbus. Users may optionally install the Nimbus Personal App or simply use the Nimbus Teams Tab in their client. Each user logging into Nimbus needs to grant User Permissions once to get full access to all (future) features.
  • GUEST MEMBERS are not considered within Nimbus. As such they are not part of the call distribution and may not log into Nimbus and its related applications.

(lightbulb) Please note that we use the terms "service" and "user" in Nimbus to differentiate between MS "teams" channels and its "members" respectively.

Administration Roles

TENANT ADMIN Tenant Admin permissions are not tied to a particular team, but required for Nimbus Installation in your company tenant. A tenant admin deploys the Nimbus app manifest for employees, runs a Powershell script to grant Required Permissions to Nimbus. As tenant admin you may also change Service Settings on already existing Nimbus team to make adjustments in their configuration. In extension to the Tenant Admins can also access the Administration backend.

  • Nimbus uses an own set of detail Roles and Permissions. These privileges can be granted optionally to allow users to potentially fulfill multiple roles at the same time.
  • The prerequisites below are mainly addressed at Tenant Admins or users with similar roles in your company.

Script Impersonation Permissions

Nimbus is deployed and (re)configured using Powershell scripts.

External Communication

External access required

TENANT ADMIN You need your tenant to allow external communications with

(tick) Necessary configuration steps are described in the Microsoft Teams Documentation: Manage external Access.

(question) Why is this necessary? If this is not done then Nimbus calls won't get through as the presence cannot be read.  All Nimbus users will be shown as offline and cannot get call invitations.

PSTN Licensing

Transfer to PSTN Limitation

Out of box Nimbus and affiliated addons can only perform PSTN transfers according to Microsoft services licensing & constraints.

(tick) As a tenant administrator you need to acquire and assign the following licenses to the application instance of the respective Nimbus SOURCE service (team) that will act as PSTN transferor:

Your SetupRequired License
Hybrid with DR Trunks"Microsoft 365 E1/E3" + "Phone System" 
"Microsoft 365 E5"
(Phone System is already included)
Hybrid with Calling plans"Phone System - Virtual User"
+ Domestic
(and optionally international) calling license

Online Only

How does PSTN licensing affect Service and Call Transfers?

Assuming that Service A has a PSTN transfer license assigned - but further Services B, C, D... don't - the following scenario may unfold:

    1. Service A workflow is configured to transfer the caller to Service B. Both are Nimbus services. No PSTN license is required at this point.
    2. Service B accepts the call. Now the workflow of Service B contains a transfer to PSTN, to which the following PSTN licensing restrictions apply:
      1. If Service A does have a PSTN license the transfer to PSTN will work from Service B. The PSTN license from Service A applies.
      2. If Service A doesn't have a PSTN license but Service B does have one, the transfer PSTN will not work. The PSTN license from Service A still applies after a Service to Service transfer.


  • For one first-level-response Service: If you handle first-response calls always via the same Service you need a PSTN license for that particular first-level Service.
  • For multiple first-level-response Services: If you handle first-response calls always via multiple Services you need a PSTN license for all those first-level Services.
  • Nimbus will attempt to use the PSTN license of the first service that responded to a call, regardless of how many further internal service transfers are performed thereafter.
  • If no PSTN license is found on a service that requires it for a transfer, the transfer task will be considered as failed and be treated as such by the system (e.g. workflow exit announcement, reporting "transfer failed" outcome).

(warning) Note that handling and tracking of running cost for PSTN licenses is outside of Luware support scope.
If you require assistance in extending and/or configuring your Nimbus services for PSTN our support will gladly assist you:You can reach us via the following means: 

(info) External reference: Microsoft Teams add-on licenses.

Phone Number configuration

When managing your Phone Numbers for usage of Nimbus services, please note the following:

  • If you're using "Direct Routing" (Numbers managed outside of Teams) you can assign any phone number to a Nimbus service.
  • If you're using calling plans for Microsoft you can only assign a "Service" number type. "User (subscriber)" type numbers will not work.

Further information can be found on in the MSFT documentation: Types of phone numbers used for Calling Plans.