How to federate Office365 Lync with Lync On-Premise

The ability to integrate on-premise systems with their Office 365 counterparts (federation) is a major attraction to many corporations as it allows users to seemlessly communicate and collaborate as if the federated solutions were one complete system. Lync is no different. For many who have Lync 2010 On-Premise, being able to federate with the Office 365 Lync Online component is vital for seamless Lync communication between the contacts held within the two systems.

Certainly, the standard Lync 2010 documentation information seemed to imply that when the Lync Online, Open Federation operation was selected on your web admin console, you could federate with any On-Premise Lync installation that also had open federation setup.

After much testing we found that this was not actually the the case. Our system is Open federation and already federated to Microsoft (not that that appears relevant), but when we added contacts it didn't give our contacts' presence. This is what our federated Lync looked like prior to us finding a fix.

Initially no presence

After some testing with a fellow Microsoft MVP, Thomas Lee who also happens to be an Office 365 guru, we found a method to federate our Lync 2010 On-Premise installation at Modality Systems with Office 365 Lync Online.

The solution that we eventually found is that you need to add a new Hosting Provider for the Office 365 Lync Online. Let's go through the setup. First ensure that the Lync Online Federation is turned on by first accessing the Office 365 admin control panel and selecting the Lync Manage option.

Once in the Online Lync control panel, select the External communications option to display the domain federation Edit button

When you click on the Edit command button, you will be given an option to turn on federation with everyone who is not in an exception list (blacklist) or turn on federation with specific systems only (whitelist). Both settings can federate your Lync Online with your Lync On-premise systems.

When federation has been enabled with all external communications, this is what you will see in the Office 365 Lync Online Control Panel.

Once you have ensure your Office 365 Lync Online has been enabled for federation, you now need to configure your Lync On-premise system. By default, Lync On-premise has three providers that Lync already provides federation with.

To add your Office 365 Lync Online, click the new hosting provider and add your Lync Online domain name as show in the screen below.

For those of you who know and use PowerShell, you can bypass the console and run the following command in the Lync Management shell:

New-CSHostingProvider -identity LyncOnline -ProxyFqdn sipfed.online.lync.com -Enabled $True

If you have used the PowerShell method, refresh the Lync On-Premise Control Panel. Which ever method you use to add the provider, you should now see your new hosting provider.

Once you have setup the systems, leave them for a few minutes to synchronise, once the CMS has had a minute or two to sync, everything should work fine.

So it seems On-Premise deployments will need to add this hosting provider to allow anyone using Office365 to federate.