The carrier communicates with Microsoft Teams using a cloud-based Teams connector. The One-Click Second Generation (2nd Gen) connector uses the existing global bespoke global SBC network, and it also routes media traffic through the updated carrier-grade SBC media clusters. This provides a wider range of audio codecs, better handling of transfers and faster response times.


The upgrade to 2nd Gen in actioned through a portal button that will reconfigure the Teams connector automatically but requires some preparation and planning before starting the process

Pre-Flight Checks

Before invoking the upgrade process there are a few things to verify:

  • Only a Microsoft 365 Global Admin user in the organisation has the authority to invoke the process so you’ll need to have a login with those permissions.
  • Check the Upgrade Teams Connector button is visible to you
  • The upgrade process uses an unassigned licence from your Office 365 account so you’ll need to ensure there is at least one available in the tenant
  • Think about when you want the upgrade process to go ahead as there will be an interruption to service whilst it’s taking place.


The following sections describe each of these items in detail.

Before Upgrading

You will need to check which Teams connector variant you are currently using. Use your admin access to the portal and go to the Services page and then the Teams tab. 

The variant is shown on the left. 'One-Click' and ‘Classic’ refer to the 1st generation connector, whereas the 2nd generation will say 'One-Click 2nd Gen'.


If your service provide has enabled the Connector upgrade, this will show a blue button with “Upgrade Teams Connector”


When you have confirmed you are using the 'One-Click' connector and have the blue button to upgrade to the 2nd Gen connector, you are ready to plan the upgrade process.


Checking you have the unassigned available Microsoft licence


Have your Global Admin login credentials to hand


Browse to https://admin.microsoft.com/ and login to the Microsoft 365 admin centre


Next go to the Billing section and the Your Products area:


In the list you’ll see whether there are any unused licences available. For example, above we can see one E3 licence but no E5 licences are available.


For the upgrade we’re going to need at least one (preferably two) unused licences of any the following types:

  • Microsoft 365 Business Basic
  • Microsoft 365 Business Premium*
  • Office 365 E3
  • Office 365 E5*
  • Common Area Phone*
  • Skype for Business Plan 2


If you don’t have any unused licence of this type, then the options are:

  1. Take the 25-user free trial offer of one of the available licences denoted with a * in the list above, or 
  2. Purchase additional Microsoft 365 Business basic subscription for a few hours and then cancel.

We don’t recommend doing the setup without an unassigned licence as it requires manual intervention that extends the time that the service is unavailable.


Scheduling the upgrade

Be aware that upgrading is disruptive and can result in users being without service until all settings have been applied and Microsoft have propagated any changes through their network.


For production/live accounts we suggest scheduling the work for an out-of-hours service window, preferably for example, the evening before a weekend. We recommend this since on rare occasions, Microsoft may take several hours to fully provision their side of the service so we recommend customers allow as much time as possible for the upgrade.


Under optimal conditions the upgrade process is completed in under 20 minutes, but it’s prudent to allow a window of several hours to mitigate any impact of delays within Microsoft’s back-end systems.


We occasionally see some delay that may be up to an hour or so for outbound calls to start working again once the upgrade is complete. The delay is due to Microsoft caching the old voice routes used by the 1st gen connector and the time this takes to clear depends on the load on the Microsoft 365 platform.


Running the Upgrade Process


Log in to the Call2Teams portal with the Microsoft 365 Global Admin user rights


Click on the services menu and the select the Teams tab.

Make sure you have the available licences and then click the blue Upgrade Teams Connector button and the process will run automatically. 


The upgrade process requires permission from you as an administrator and may request that you approve access during the upgrade process. This is the same access you granted the portal during the initial set-up, and requires similar changes to be made to the tenant.  From the point this button is pressed until the process is complete, calling for Teams users will be offline.

Please note that this perform a process similar to the original setup of your account so will take a similar time. 


Occasionally Microsoft will not complete the updates in their system and the Sync Now button may need to be pressed again, you may see this error:

This error is not unusual when Microsoft 365 is under heavy load. Simply follow the instruction to Sync again.


When the process is complete you will see the connector listed as One-Click 2nd Gen and the green Checkmark on the Sync Now button confirms the Microsoft 365 tenant is set-up completely and settings are validated. 

Make some test calls to verify the operation of the new connector, raise any issues with your service provider.



There should be no changes required to the service or user configuration following the upgrade.

However, if you were previously on the ‘Classic’ Teams Connector then you are now free to remove the DNS records that you published during your original setup.