Applies To

Call2Teams - Customers


Call2Teams 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.

Adding The New Variant

Checking Availability of the Service

The One-Click 2nd gen service has to be added to your account by your partner. If you are a Microsoft Direct Customer or your support channel is direct with Qunifi, you will need to raise a case with us to have this enabled.

How Do I Upgrade

We advise that all upgrades should be performed out of hours as retiring the existing connector will result in loss of service until users have been reconfigured and synchronization has completed successfully.

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 Call2Teams 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 2 earlier connectors that were available. Where the variant displays 'One-Click 2nd Gen', this refers to the latest 2nd Generation Teams Service Connector.


If your Partner has enabled the Connector upgrade, this will show a blue button displaying the text, “Upgrade Teams Connector”


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


Checking you have an unassigned available Microsoft licence

Have your Global Admin login credentials to hand


Browse to and login to the Microsoft 365 admin center

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. This is line with any initial Sync:

  • 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.


Please ensure the new port ranges have been added to your firewall allowed list before the upgrade.

The media ports for the legacy setup is 20000 to 29000

The media ports for 2nd gen is much wider, 6000-65535


Scheduling the upgrade

Be aware that upgrading is disruptive and can result in users being unable to make or receive PSTN calls 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 generation 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 performs a process similar to the original setup (Synchronization) of your account so will take a similar time. 


Occasionally Microsoft may not complete the updates in their system and you may see this error: 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 click the Sync Now button  again or 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 Partner.


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.


What If I Need To Revert To An Earlier Connector?

This should not normally be a requirement, but these instructions are provided should there be any concerns following an upgrade.

Before Reverting

You will need to check which Teams connector variant you are currently using. If you have access to the portal, you can do this by going to the Services page and then the Teams tab. The variant is shown on the left. 'One-Click' refers to the 1st generation connector, where as the 2nd generation will say 'One-Click 2nd Gen'. You may need to confirm with your Partner that the required variant is still available.



If you have the 'One-Click 2nd Gen' variant, then you may be asked to revert for PBX compatibility reasons.


The Revert Process

You should firstly be aware that reverting is disruptive and as with the initial synchronization can result in users being without service until all setting 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.


  • Start by taking a note of which Teams users are linked with which SIP identities. Once the Teams service is deleted and re-created the SIP identities will need remapping with the appropriate Teams user. For our example here we noted down the three user's names and SIP usernames:

  • With the user information stored you can now delete the service. From the Services page >Teams tab, click the delete Trash Can. This will remove the Teams Service. At this point, your Teams users will be unable to use the Teams app to make/receive PTSN calls until the process is complete.
  • With the old service removed, enable the service again via the same Services>Teams tab. Select the ‘One Click’ Variant and the click Enable Service:

Note: You may not get an option for Service Variant. As long as your Partner has confirmed the appropriate variant is enabled on your account, this is fine.


  • The new service will start an initial sync. As soon as this starts, you will be able to confirm you are now configuring the One Click connector by viewing the Services page > Teams tab:



  • The first sync takes around 15 minutes on average, as new custom domains are configured on the account. If you don't have a spare licence you will need to change a user login domain temporarily (the same steps as required by upgrading the 2nd Generation connector). You can also see further options on spare O365 licences here: Spare Licence Options
  • The sync button will give details of its current status and alert if actions are required:

  • With the first sync complete you will need to reconfigure your users. Users on the platform consist of two parts, a PBX/trunk part plus a Microsoft part. The original PBX/trunk parts will have been retained. You will need to expand each row and select the appropriate Teams user for the SIP details shown. For example continuing our example from earlier:

  • Once complete, the users will show configured again and the portal will prompt for a second sync to push the user configuration to Microsoft:

  • Finally when the sync is complete the users are ready to receive calls:



You should only go through the revert process if directed to do so. As noted above, ensure SIP details are retained and the process is executed out-of-hours for in-use production accounts.


We often see some delay in outbound calls working again once the upgrade is complete. Typically this takes a couple of hours. The delay is due to Microsoft caching the old voice routes used by the 2nd Generation connector.



Please note Qunifi cannot be held responsible for the content of any third-party documentation offered.