Lync – Office 365 Federation Presence Unknown
A customer was having problems with their Lync 2010 deployment federating with Office 365. When searching for a Lync Online user they would see “Presence Unknown” and be unable to send Instant Messages. They could Federate with other On-Prem Lync organisations OK. They had LyncOnline configured as a Hosted Provider and Partner Domain Discovery Enabled (Dynamic Federation). Their _sipfederationtls._tcp DNS record was configured correctly as was the O365 customer. Using OCSLogger and Snooper on the Edge server I was able to spot the problem. ...