This failure can be caused by network performance issues affecting the endpoints or an endpoint being unable to use the A/V Edge Server. The most common cause for this is that a legacy client in the conversation needs to be patched (KB 2028888).

The unknown endpoint is most likely a legacy client, legacy component or third party application. The call failed to establish due to a media connectivity failure. Timed out waiting for the remote party to update the dialog route setĬall failed to establish due to a media connectivity failure where one endpoint is of unknown type Wait for dialog route set update timed out Recovery action to re-register and update dialog route set failed Recovery action to update dialog route set failed

Caller’s user Policy block the call from being re-routed through PSTN There is not sufficient bandwidth to establish the session. Insufficient bandwidth to establish session. Attempt to reroute request to establish session Do not attempt to reroute this session request The server cannot forward request originally addressed to the TO user to the location specified in the request URI

Here’s a handy table of all of the Lync Diagnostic codes and their descriptions: Diagnostic IDĭefault error code used by a component if it is adding only one ms-diagnostics header for all failure scenarios

Skype call internal error