Federate with Lync Online

To federate with Lync Online/Office 365, run:

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

Enable-CSTopology
 

Here’s how to do it using GUI: http://techietom.co.uk/blog/2011/04/how-to-enable-office365-lync-online-to-federate-with-lync-on-prem/