You may have already allowed the federated domain in the Lync Control Panel but you may find yourself unable to federate with a specific organisation. The remote contact state will be shown as “Presence Unknown”. The first step I did was to enable logging within the Lync client before attempting to send a message to the affected user. The log file can be read using a tool called snooper and can be found in the Lync resource kit. After opening the log with Snooper and select the messages tab and search for the remote contact. In this particular case the below error was received:

ms-diagnostics: 1047;reason=”Failed to complete TLS negotiation with a federated peer server”;WinsockFailureCode=”10054(WSAECONNRESET)”;WinsockFailureDescription=”The peer forced closure of the connection”


In this scenario the remote partners Edge server did not trust the CA that issued certificate assigned to ours. The remote partner needed to install the root CA of our Edge Server, on their Edge server in the Trusted Root Certification Authorities Store to resolve this.

About the author