Problems with Lync Web App from external


  • Hi, i have a problem i have been struggling with. First of all, the setup looks like this:

    Windows Server 2008 R2 SP1, fully patched.

    Lync enterprise Front-End servers internally

    Lync Edge in Perimeter network.

    Microsoft TMG for reverse proxy

    This is what works:

    * Internal and External Lync Full client signin/im/presence/ab/video/voice etc..

    * Internal Online Meeting with Web App/Attendee/Full Lync Client

    * External Online Meeting with Attendee/Full Lync..

    But here comes the problem.. external Lync Web App does NOT work. When I initially click on the meeting url it looks like this, After I click on that link and if the computer I'm testing on does not have the lync client or the lync attendee, I am presented with a page that gives me the option to "Join the meeting using your web browser" or "Download and install Lync Attendee". If i have the attendee or the lync client, there are no problems. If I click on Join the meeting using your web browser, I immediately see a pop-up client looking window. The URL in the window is a bunch of other stuff. The error I get is "The meeting link you are using to join is not valkid. Please check the link and try again."

    I have checked TMG, the edge server, and the lync pools and I don't see anything wrong. Any help in pointing me in the right direction would be helpful.

    Thursday, August 30, 2012 5:09 PM

All replies

  • Hi,

    please make sure you have create the A record of lync external web service in the internet and add the external web service FQDN to the TMG certificate san list.

    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    Monday, September 03, 2012 8:37 AM
  • So If i check my enterprise pool on the lync topology builder, I assume the "Web services" is what I want to verify right? There is an internal and an external web services. Internal is disabled and external is I have also verified that is present in the SAN on the cert on lync and on the lync edge server and tmg. I also have webconf published on TMG and an external A record created for webconf. What am I missing here?

    When users go to join a meeting, the url is where they are presented with a site that gives them the option to join the meeting using their web browser. When they click on the join meeting using web browser, another window pops up but the url is Any ideas here?

    Tuesday, September 04, 2012 2:41 PM
  • Hi,

    I hope you don't misunderstand the Edge web conferencing service and Lync External web service. The external web services work for internet Lync Web App. You can set it in the topology builder--Pool Name--Edit properties--Web services--External Web services. You can set the FQDN of the External web Services as The FQDN, tt should be different from Edge web conference services.

    The lync web App uses the TMG to join the meeting, but the other lync clients use the Edge Server to join the meeting. So I think there are somthing wrong with the reverse proxy server. Please check the TMG configuration again. If still can not work, please get more logs about the issue on the TMG server.

    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    Monday, September 10, 2012 3:14 AM
  • In the topology builder, under the Simple URLs header, my meeting url is set to If I click on the root of the enterprise edition front end pools, my external web services fqdn is That being said, in TMG my reverse proxy is setup to forward all requests to webconf and meet directly to the front end pools VIP (keep in mind, this was working), not the edge server. The TMG rule is set to bridge the connection to 4443 and If i run a test on the rule in TMG, it is successful on the configured paths.

    Again, the meeting works external if you download the lync attendee or if you already have a client. It just doesn't work if you want to use lync web.

    Monday, September 10, 2012 4:05 AM
  • Hi Justin did you manage to resolve the problem ?

    I'm stuck in that situation too.

    Lync Attendee or Lync Client are working flawlessly from the external. When I start Lync Web App I don't get "Guest" or "Corporate" buttons and I receive only "The meeting link you are using is not valid"

    I double checked TMG Certificates and rules but everything seems to be OK .

    From the TMG console I can see that my client is getting URL like this


    When I open that URL (with https in front) Lync Web App is working

    edit: I end up here with that error on my Lync FE Server (standard edition BTW)

    failed to validate the conference key: request ID = 26, reason=conferenceDoesntExist, diagnosticsInfo=key=ms-diagnostics;value=4000;reason="User services default";source="srv-lync.domain.local"

    It seems that TMG brake the Link that is parsed to the FE Server.

    Friday, September 14, 2012 8:47 PM
  • Did you get a solution to this? I have the exact same setup, everything works Internally and externally, the only external problem is Web app fails, with a this meeting is invalid error.
    Friday, September 21, 2012 12:15 PM