We have a intermittent problem for users connecting to Lync from inside our corporate network. The symptom that brought this issue to our attention is a failure to contact the sharing server during online meetings. On each of the clients, config info show that the connection is through the edge (Inside user status: FALSE)
Why would it be connecting to the edge? We don't have DNS records for our edge servers published in internal DNS. We do have the _sipinternaltls record in our internal DNS, pointing to our Director pool.
Most of our users work from home some of the time. My theory is that the client has stored the connection information when it was used at home and connected through the edge. When the user moves to the office, the client connects to the edge again, without going through the SRV discovery process. As I mentioned before, there are no DNS records for the edge services, but it is possible to contact the edge by IP address.
Is this behavior expected? Other then blocking connections from inside our network to the edge server external IPs (very difficult considering the number of office networks we have), is there a way to stop this behavior?