I'm running into a weird issue:
Lync Client fully works internally and externally
Lync Web fully works internally and externally
Lync Mobility fully works internally and externally
Lync Attendee fully works internally but won't connect externally
When I put in a guest name or user@sipdomain and hit connect it immediately errors out: "Cannot connect to the online meeting. Cannot connect to the meeting because of a problem connecting to the server. If the problem continues, please contact your support team."
DNS is correct, SRV records exist and are resolvable (_sip._tls. and _sipfederationtls._tcp.) Certificates are signed by a public CA, intermediate and root certificates from the CA are installed on both the edge server and reverse proxy.
I have an edge server and front end, no director in the topology.
I'm stumped... wondering what to check/test.