Lync Server Mobility Troubleshooting Tips

The Lync Mobility service and the Lync Clients was released 13.12.2011. Since then as we get more hands-on with the service there are in some cases trouble getting the it up and running. This post is dedicated to how you can test and troubleshoot the mobility service deployment. I will update this post when I find more information on how to troubleshoot and how to solve certain scenarios.

Last updated: 14.10.2012


If you have a multi-homed Front End server the Mobility Service (Mcx) may sometimes fail

  • Reason: When calculating routing for a Mobility request the service makes a call to read DNS settings of the registered adapter. In some instances it is possible for the non-registered adapter to be returned.
  • This causes routing of the request to fail This is regardless subnet configuration on the second NIC
  • There should be a forthcoming Release Note or KB Article on this topic

Make sure you have deployed the solution correct by following one of these guides created by myself and fellow MVP’s Jeff Schertz and Adam Jacobs.


To validate the installation and configuration on the server side before you involve clients use the following techniques

To check that Autodiscover is working as expected, check the Autodiscover urls in a webbrowser

  • Get-CsService -WebServer | fl  autodiscover* to find the urls
  • Example: https://<Webservices URL>/autodiscover/autodiscoverservice.svc/root
    • Note: Make sure you don’t have “/” after root, because then you just get a “Endpoint Not Found” page
  • You should get to download the root file stating the following: {“AccessLocation”:”External”,”Root”:{“Links”:[{“href”:”https…… and so on pointing to your Webservices URL

Use to validate external web service Autodiscover

To check  that the mobility service is working use the following url

You can test the Push Notificaton Service using the following cmdlet where is you AccessEdgeFQDN

You can test the Mobility Service using the following script, at this time it does not work with preconfigured CsHealthMonitoringConfiguration

$passwd1 = ConvertTo-SecureString "Password01" -AsPlainText -Force
$passwd2 = ConvertTo-SecureString "Password02" -AsPlainText -Force
$tuc1 = New-Object Management.Automation.PSCredential("contoso\UserName1", $passwd1)
$tuc2 = New-Object Management.Automation.PSCredential("contoso\UserName2", $passwd2)
Test-CsMcxP2PIM -TargetFqdn -SenderSipAddress -SenderCredential $tuc1 -ReceiverSipAddress -ReceiverCredential $tuc2 –v


You can find a thorough Lync mobile troubleshooting article at NextHop:

Microsoft has released CU4 release notes with known issues for Lync Mobile and workarounds. I have listed some of the most important issues here

  • Issues with switching between Wi-Fi and 3G with Lync Mobile for Windows Phone. Resolution: Exit Lync Mobile and start Internet Explorer to reestablish network connectivity
  • Lync might not connect to an IM conversation from push notification on Lync 2010 for Windows Phone. Resolution: Conversation must be reestablished because of timeout or the conversation was answered on another device
  • In iOS, not all Lync meetings show up as Lync meetings. Resolution: Expected behavior when the meeting is scheduled by copying the Lync Online link, created in webaccess or created by Lync Online user that is not enabled for the audio conferencing provider (ACP)
  • Push notification over a Wi-Fi network requires that firewall UDP port 5223 is open for incoming HTTP traffic. Resolution: This is because of Apple Push Notification service requires it

Download the release notes here:

Other issues that may occur and are described by Microsoft

I have seen an issue where Call via Work does not work. When you use Call via Work Lync will dial the phone number you have specified only to get disconnected when


  • When you use Call via Work Lync will dial the phone number you have specified only to get disconnected when you try to answer the call
  • In the Lync server SIP logs you see a 603 Decline message from the SIP Trunk GW


  • Use Lync Server Management Shell to verify that Get-CsTrunkConfiguration | fl EnableReferSupport is set to True
  • If it is you can try to set it to false
  • Set-CsTrunkConfiguration -EnableReferSupport $False
  • Now try the Call via Work feature and it should work
  • The reason for this is that the SIP Trunk provider is not configured to support SIP REFER

You may have the problem with users not being able to sign in. Make sure the following is true

  • Go through the logs from the sign in process, Lync Mobile has the ability to send diagnostic logs from the client to the administrator
  • Lyncdiscover is a CNAME pointing to Web Services URL found using Get-CsService -WebServer | ft ABHandlerExternalUri
  • The certificate on the ISA/TMG is updated with the SAN
  • If it is over Wi-Fi and users connect internally the clients must trust the Root certificate used on the Front End server
  • If you are using port 80 make sure you are using a separate publishing rule, listener is configured for 80->8080 and no authentication and clients can not authenticate is set
  • The Lync Mobile client can’t sign in and you get a 401 unauthorized in the logs, may be due to multiple NIC’s on the FE:
  • The Lync Mobile client can’t sign in when you publish LoadBalanced FE using TMG Web farm for the web services, try switching your TMG persistence to source IP:
  • See MVP Jeff Schertz on Lync Mobile iOS Client Authentication Issues:
  • Notice that only iOS and Android Phones can sign in but not WP? And when you check the Lync Mobile logs it states: DiscoveryFailedToFindRoot?

Troubleshooting articles

A good Lync Mobile troubleshooting story by flinchbot:
Lync 2010 Mobility Sign-in Process:
Windows Phone 7 mobile devices: use and troubleshooting:
Google Android mobile devices: use and troubleshooting:
Apple iPhone and iPad mobile devices: use and troubleshooting:
Lync Online Troubleshooting “Cannot connect to the server” errors on Lync mobile devices:
Lync Mobility – Understanding SIP Sign-in Address vs. User Principle Name (UPN):

21 thoughts on “Lync Server Mobility Troubleshooting Tips

    • Have you restarted the services? I also get 403 error but only trying using http and not https. As for the autodiscover issue, make sure you are trying it externally. I have as well a deployment with the same error. Will get back to you when I find out more


      • I`m also getting the “Endpoint not found” when testing the autodiscover URL. Anyone have any ideas?

      • Hi. Found the reason for Endpoint Not Found. “https://webservicesfqdn/autodiscover/autodiscoverservice.svc/root” must be without “/” at the end. Then you will see that the root file will download. Also, make sure that you dont have more than one NIC on the FE as stated in the beginning of the blogpost. I have corrected the URL in the blogpost


        • HI Ståle,

          I’m back at work today so went through the steps.

          Hitting: https:///mcx/mcxservice.svc actually said it started the service and it was available. From that point on, I’ve been able to get mobile clients working on all platforms.

          Thanks for writing an extremely detailed and helpful article.



  1. Ståle good post especially on Call from Work issue and resolution.

    Disabling REFER on the SIP trunk has fixed the issue for me where my phone would ring but no connection would be made to the 3rd party.

    Server also needed a reboot.


  2. A little uncertain about one thing.
    To get the push-notification working, why should i need to make a federation against ? Is that service only available in the cloud?

    All my Microsoft servers are on-premises.

  3. I have some problems with clients. Every test is OK, Android Client succesfully connect to server, but can’t see presence status. Other clients WP7 and iOS won’t connect. How can I troubleshoot it?

  4. I have a question on expected behaviour of the IOS app, if someone IM’s me and puts “hi tony” and I miss answering the incoming Lync IM, should I always see the initial message itself, the “hi tony” inside the app when i get round to opening it ? Or are there circumstances that the content will not be present ?

  5. I have setup the Lync Discovery process and it working fine for all client except LyncMX, during my investigation I figure out than my url return the internal information if I use the 80 reverse proxy but External information are return when using 443. Since we have a lot of SIP domain the 80 reverse proxy was what we needed.

    Any idea why this is happening ?


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